Melasma NT Cream

Niacinamide

Niacin (nicotinic acid or 3-pyridinecarboxylic acid) is a B-complex vitamin. Good dietary sources of niacin are animal proteins, beans, green vegetables, liver, mushrooms, peanuts, whole wheat, and unpolished rice. Niacin is also present in cereal grains but is largely bound to plant proteins, and thus is poorly absorbed after ingestion. Niacin is one of the substances used in the enrichment of refined flour, and our dietary intake of pre-formed niacin comes primarily from enriched grains. However, the body’s niacin requirement is also met by the biosynthesis of niacin from tryptophan, an amino acid. For example, milk and eggs do not contain niacin, but do contain large amounts of tryptophan from which niacin is derived. Each 60 mg of excess tryptophan (after protein synthesis) is converted to approximately 1 mg of niacin. Synthesis of the vitamin from tryptophan in proteins supplies roughly half the niacin requirement in man. Iron-deficiency or inadequate pyridoxine or riboflavin status will decrease the conversion of tryptophan to niacin and may contribute to deficiency, due to an interdependence of coenzymes in the niacin production pathway. A late and serious manifestation of niacin deficiency is pellagra, a clinical symptom complex principally affecting the GI tract, skin, and CNS, producing symptoms of diarrhea, dermatitis, and dementia, respectively. Pellagra may result from a niacin- and protein-deficient diet, isoniazid therapy, or certain diseases that result in poor utilization of tryptophan. Pellagra was the only vitamin-deficiency disease to ever reach epidemic proportions in the US; pellagra is rare today in industrialized countries due to the enrichment of refined flours.

Several synonyms for niacin and niacinamide exist. Synthetic niacin could be produced by the oxidation of nicotine, and the term ‘nicotinic acid’ evolved. Scientists also coined the terms ‘nicotinamide’ and ‘niacinamide’ for the amide form of nicotinic acid. The term ‘niacin’ has been used generically since the 1940’s to label foods and to avoid association of the vitamins with the nicotine alkaloid from tobacco. Thus, the name ‘niacin’ has been used to denote both chemical forms, which are equivalent as vitamins on a weight basis. Both nicotinic acid and nicotinamide are synthesized for inclusion in nutritional supplements. However, since nicotinic acid and nicotinamide have different pharmacologic properties outside of their use as vitamins, it is important to distinguish between the two forms in pharmaceutical products.

In clinical medicine, nicotinic acid is used as an antilipemic, but nicotinamide (niacinamide) is not effective for this purpose. Nicotinic acid was the first hypolipidemic agent shown to decrease the incidence of secondary myocardial infarction (MI) and reduce total mortality in MI patients. However, no incremental benefit of coadministration of extended-release niacin with lovastatin or simvastatin on cardiovascular morbidity and mortality over and above that demonstrated for extended-release niacin, simvastatin, or lovastatin monotherapy has been established. In addition, the AIM-HIGH trial demonstrated that the concurrent use of extended-release niacin (1500—2000 mg/day PO) and simvastatin does not result in a greater reduction in the incidence of cardiovascular events than simvastatin alone. These results are consistent with those of the larger HPS2-THRIVE trial in which the addition of extended-release niacin to effective statin-based therapy did not result in a greater reduction in the incidence of cardiovascular events. Furthermore, there was an increased risk of serious adverse events including an increased incidence of disturbances in diabetes control and diabetes diagnoses, as well as serious gastrointestinal, musculoskeletal, dermatological, infectious, and bleeding adverse events. There was also a statistically insignificant 9% proportional increase in the incidence of death from any cause in the niacin group. The ARBITER 6-HALTS trial demonstrated that the addition of extended-release niacin 2000 mg/day to statins results in significant regression in atherosclerosis as measured by carotid intima-media thickness, and is superior to the combination of ezetimibe and a statin. In an MRI study, the addition of extended-release niacin 2000 mg/day to statin therapy resulted in a significant reduction in carotid wall area compared to placebo. However, the NIA Plaque study, which was presented at the American Heart Association (AHA) 2009 Scientific Sessions, did not find a significant reduction in the progression of atherosclerosis associated with the addition of niacin to statin therapy as compared to statin monotherapy. Additionally, nicotinic acid has been used as a therapy for tinnitus, but efficacy data are scant. Some sustained-release nicotinic acid formulations have a lower incidence of flushing but a higher incidence of hepatotoxicity when compared to immediate-release forms. Some dosage forms are available without prescription. The FDA officially approved niacin in 1938.

Tranexamic Acid

Tranexamic acid is an oral and injectable antifibrinolytic agent indicated for short-term use to reduce or prevent hemorrhage and reduce the need for replacement therapy during and after tooth extraction in patients with hemophilia and for the treatment of cyclic heavy menstrual bleeding. Tranexamic acid may increase the risk of thromboembolic events. Venous and arterial thrombosis or thromboembolism have been reported in patients treated with tranexamic acid. Tranexamic acid is contraindicated in patients with active thromboembolic disease or a history or intrinsic risk of thrombosis or thromboembolism. Tranexamic acid has actions similar to those of aminocaproic acid, but it is approximately 10 times more potent.

Niacinamide

Dietary requirements for niacin can be met by the ingestion of either nicotinic acid or nicotinamide; as vitamins, both have identical biochemical functions. As pharmacologic agents, however, they differ markedly. Nicotinic acid is not directly converted into nicotinamide by the body; nicotinamide is only formed as a result of coenzyme metabolism. Nicotinic acid is incorporated into a coenzyme known as nicotinamide adenine dinucleotide (NAD) in erythrocytes and other tissues. A second coenzyme, nicotinamide adenine dinucleotide phosphate (NADP), is synthesized from NAD. These two coenzymes function in at least 200 different redox reactions in cellular metabolic pathways. Nicotinamide is released from NAD by hydrolysis in the liver and intestines and is transported to other tissues; these tissues use nicotinamide to produce more NAD as needed. Together with riboflavin and other micronutrients, the NAD and NADP coenzymes work to convert fats and proteins to glucose and assist in the oxidation of glucose.

In addition to its role as a vitamin, niacin (nicotinic acid) has other dose-related pharmacologic properties. Nicotinic acid, when used for therapeutic purposes, acts on the peripheral circulation, producing dilation of cutaneous blood vessels and increasing blood flow, mainly in the face, neck, and chest. This action produces the characteristic “niacin-flush”. Nicotinic acid-induced vasodilation may be related to release of histamine and/or prostacyclin. Histamine secretion can increase gastric motility and acid secretion. Flushing may result in concurrent pruritus, headaches, or pain. The flushing effects of nicotinic acid appear to be related to the 3-carboxyl radical on its pyridine ring. Nicotinamide (niacinamide), in contrast to nicotinic acid, does not contain a carboxyl radical in the 3 position on the pyridine ring and does not appear to produce flushing.

Nicotinic acid may be used as an antilipemic agent, but nicotinamide does not exhibit hypolipidemic activity. Niacin reduces total serum cholesterol, LDL, VLDL, and triglycerides, and increases HDL cholesterol. The mechanism of nicotinic acid’s antilipemic effect is unknown but is unrelated to its biochemical role as a vitamin. One of nicotinic acid’s primary actions is decreased hepatic synthesis of VLDL. Several mechanisms have been proposed, including inhibition of free fatty acid release from adipose tissue, increased lipoprotein lipase activity, decreased triglyceride synthesis, decreased VLDL-triglyceride transport, and an inhibition of lipolysis. This last mechanism may be due to niacin’s inhibitory action on lipolytic hormones. Nicotinic acid possibly reduces LDL secondary to decreased VLDL production or enhanced hepatic clearance of LDL precursors. Nicotinic acid elevates total HDL by an unknown mechanism, but is associated with an increase in serum levels of Apo A-I and lipoprotein A-I, and a decrease in serum levels of Apo-B. Nicotinic acid is effective at elevating HDL even in patients whose only lipid abnormality is a low-HDL value. Niacin does not appear to affect the fecal excretion of fats, sterols, or bile acids. Clinical trial data suggest that women have a greater hypolipidemic response to niacin therapy than men at equivalent doses.

Tranexamic Acid

Tranexamic acid is a hemostatic agent and is a synthetic derivative of the amino acid lysine. Tranexamic acid binds to the lysine binding site for fibrin on the plasminogen/plasmin molecule. Plasminogen has 4 to 5 binding sites with low affinity for tranexamic acid and 1 high-affinity binding site. The high-affinity binding site is involved with the binding of plasminogen to fibrin. Saturation of this high-affinity binding site by tranexamic acid displaces plasminogen from the surface of fibrin. This prevents the binding of fibrin to plasmin and preserves and stabilizes the matrix structure of fibrin and diminishes the ability of plasmin to lyse fibrin clots. Tranexamic acid is about 10 times more potent in vitro than aminocaproic acid, binding more strongly to both the high and low-affinity binding sites of plasminogen.

Elevated concentrations of endometrial, uterine, and menstrual blood tissue plasminogen activator (tPA) are observed in women with heavy menstrual bleeding compared to women with normal menstrual blood loss. In women with heavy menstrual bleeding and after receiving oral doses of 2 to 3 g/day for 5 days, the effect of tranexamic acid on lowering endometrial tPA concentrations and menstrual fluid fibrinolysis is observed.

At blood concentrations as low as 1 mg/mL, tranexamic acid can prolong the thrombin time. However, at blood concentrations up to 10 mg/mL, tranexamic acid has no effect on platelet count, coagulation time, or various coagulation factors in whole blood or citrated blood in healthy subjects.

Niacinamide

Patients who have a known hypersensitivity to niacin or any product component should not be given the drug.

While steady state plasma concentrations of niacin are generally higher in women than in men, the absorption, metabolism, and excretion of niacin appears to be similar in both genders. Women have been reported to have greater response to the lipid-lowering effects of nicotinic acid (niacin) when compared to men.

No overall differences in safety and efficacy were observed between geriatric and younger individuals receiving niacin. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity for some older individuals cannot be ruled out.

Niacin is contraindicated in patients who have significant or unexplained hepatic disease. Patients who consume large quantities of ethanol (alcoholism), who have risk factors for hepatic disease, or who have a past-history of gallbladder disease, jaundice, or hepatic dysfunction may receive niacin with close clinical observation. Elevations in liver function tests (LFTs) appear to be dose related. Some sustained-release nicotinic acid (niacin) formulations have a higher incidence of hepatotoxicity when compared to immediate-release dosage forms. Extended-release nicotinic acid preparations (e.g., Niaspan, Slo-Niacin) should not be substituted for equivalent dosages of immediate-release (crystalline) niacin (e.g., Niacor and others). Follow the manufacturer-recommended initial dosage titration schedules for extended-release products, regardless of previous therapy with other niacin formulations. Monitor LFTs in all patients during therapy at roughly 6-month intervals or when clinically indicated. If transaminase levels (i.e., ALT or AST) rise to 3 times the upper limit of normal, or clinical symptoms of hepatic dysfunction are present, niacin should be discontinued.

Nicotinic acid (niacin) can stimulate histamine release, which, in turn, can stimulate gastric acid output. Niacin is contraindicated in patients with active peptic ulcer disease (PUD) because it can exacerbate PUD symptoms. Use niacin with caution in patients with a past history of peptic ulcer disease or in those on maintenance therapy to prevent PUD recurrence.

Due to its vasodilatory action, nicotinic acid (niacin) should be used with caution in those patients with uncorrected hypotension (or predisposition to orthostatic hypotension), acute myocardial infarction, or unstable angina, particularly when vasodilator medications such as nitrates, calcium channel blockers, or adrenergic blocking agents are coadministered (see Drug Interactions). Because the vasodilatory response to niacin may be more dramatic at the initiation of treatment, activities requiring mental alertness (e.g., driving or operating machinery) should not be undertaken until the response to niacin is known.

Niacin, especially in high doses, can cause hyperuricemia. Niacin should be prescribed cautiously to patients with gout (or predisposed to gout). These individuals should be advised not to purchase OTC forms of niacin without the guidance of a physician.

Niacin, especially in high doses, can cause hypophosphatemia. Although the reductions in phosphorus levels are usually transient, clinicians should monitor serum phosphorus periodically in those at risk for this electrolyte imbalance.

Rare cases of rhabdomyolysis have been reported in patients taking lipid-altering dosages of nicotinic acid (niacin) and statin-type agents concurrently (see Drug Interactions). Patients undergoing combined therapy should be carefully monitored for muscle pain, tenderness, or weakness, particularly in the early months of treatment or during periods of upward dose titration of either drug. While periodic CPK and potassium determinations may be considered, there is no evidence that these tests will prevent the occurrence of severe myopathy. If rhabdomyolysis occurs, the offending therapies should be discontinued.

Niacin, especially in high doses, may cause hyperglycemia. Niacin should be prescribed cautiously to patients with diabetes mellitus. These individuals should be advised not to purchase OTC forms of niacin without the guidance of a physician. Niacin has also been reported to cause false-positive results in urine glucose tests that contain cupric sulfate solution (e.g., Benedict’s reagent, Clinitest).

Niacin therapy has been used safely in children for the treatment of nutritional niacin deficiency. However, the safety and effectiveness of nicotinic acid for the treatment of dyslipidemias have not been established in neonates, infants and children <= 16 years of age. Nicotinic acid has been used for the treatment of dyslipidemia in pediatric patients under select circumstances. Children may have an increased risk of niacin-induced side effects versus adult populations. At least one pediatric study has concluded that niacin treatment should be reserved for treatment of severe hypercholesterolemia under the close supervision of a lipid specialist. In general, the National Cholesterol Education Program (NCEP) does not recommend drug therapy for the treatment of children with dyslipidemias until the age of 10 years or older.

Since niacin is an essential nutrient, one would expect it to be safe when administered during pregnancy at doses meeting the recommended daily allowance (RDA). Niacin is categorized as pregnancy category A under these conditions. However, when used in doses greater than the RDA for dyslipidemia, or when used parenterally for the treatment of pellagra, niacin is categorized as pregnancy category C. Most manufacturers recommend against the use of niacin in dosages greater than the RDA during pregnancy. The potential benefits of high-dose niacin therapy should be weighed against risks, since toxicological studies have not been performed.

According to a manufacturer of niacin (Niaspan), although no studies have been conducted in nursing mothers, excretion into human milk is expected. The manufacturer recommends the discontinuation of nursing or the drug due to serious adverse reactions that may occur in nursing infants from lipid-altering doses of nicotinic acid. Niacin, in the form of niacinamide, is excreted in breast milk in proportion to maternal intake. Niacin supplementation is only needed in those lactating women who do not have adequate dietary intake. The Recommended Daily Allowance (RDA) of the National Academy of Science for niacin during lactation is 20 mg. There are no safety data regarding the use of nicotinic acid in doses above the RDA during breast-feeding. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

Use niacin with caution in patients with renal disease (renal failure or severe renal impairment) since niacin metabolites are excreted through the kidneys. It appears that no special precautions are needed when administering niacin to meet the recommended nutritional daily allowance (RDA). Use caution when administering higher dosages.

Nicotinic acid (niacin) occasionally causes slight decreases in platelet counts or increased prothrombin times and should be used with caution in patients with thrombocytopenia, coagulopathy, or who are receiving anticoagulant therapy. Patients who will be undergoing surgery should have blood counts monitored. Nicotinic acid (niacin) is contraindicated in patients with arterial bleeding.

The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents (e.g., geriatric adults) of long-term care facilities (LTCFs). According to OBRA, glucose and liver function tests should be evaluated regularly because niacin interferes with glucose control, can aggravate diabetes, and can exacerbate active gallbladder disease and gout. Flushing is a common side effect of niacin.

Tranexamic Acid

Tranexamic acid is contraindicated in patients with a known hypersensitivity to tranexamic acid or any of the ingredients. Severe allergic reactions have been reported.

Injectable tranexamic acid is contraindicated in patients with active intravascular clotting. Oral tranexamic acid is contraindicated in patients with active thromboembolic disease (e.g., deep vein thrombosis, pulmonary embolism, or cerebral thrombosis), a history of thrombosis or thromboembolism, including retinal vein or artery occlusion, or an intrinsic risk of thrombosis or thromboembolism (e.g., thrombogenic valvular disease, thrombogenic cardiac rhythm disease, or hypercoagulopathy).

Injectable tranexamic acid is contraindicated in patients with subarachnoid hemorrhage (intracranial bleeding). Cerebral edema and cerebral infarction may be caused by the use of tranexamic acid in patients with subarachnoid hemorrhage.

Injectable tranexamic acid is contraindicated in patients with acquired defective color vision as this condition impedes appropriate monitoring for ocular toxicity. Retinal venous and arterial occlusion have been reported in patients taking tranexamic acid. In patients who are to be treated continually for more than several days (or more than 3 months), obtain an ophthalmological examination including visual acuity, color vision, eye-ground, and visual field before initiation and at regular intervals during treatment. Discontinue tranexamic acid if a visual disturbance is seen during examination.

Tranexamic acid is substantially excreted by the kidneys, and the risk of adverse reactions may be greater in patients with renal impairment. Reduce the dosage of tranexamic acid in patients with renal insufficiency due to the risk of accumulation.

Patients with disseminated intravascular coagulation (DIC) who require treatment with injectable tranexamic acid requires an experienced clinician in treating this disorder.

Seizures have been reported with tranexamic acid use, particularly in patients receiving tranexamic acid during cardiovascular surgery (which is not FDA-approved and uses doses up to 10-fold higher than the recommended human dose) and in those inadvertently given tranexamic acid into the neuraxial system. Consider dosage reduction during surgery and dose adjustments in patients with renal dysfunction. Closely monitor patients during surgery. Consider EEG monitoring in patients with a history of seizure disorder or who experience myoclonic movements, twitching, or show evidence of focal seizures. Discontinue tranexamic acid if seizures occur.

Tranexamic acid may cause dizziness. Advise patients to avoid driving or operating machinery until they know how the drug affects them. Use caution in dose selection for the geriatric patient, usually starting at the low end of the dosage range, reflecting the greater frequency of decreased renal function in this population. Because tranexamic acid is substantially excreted by the kidney, risk of toxicity may be greater. It may be useful to monitor renal function. Clinical experience has not identified differences in response to injectable tranexamic acid between geriatric and younger patients; clinical studies did not include sufficient numbers of patients aged 65 years and older.

There are no adequate or well-controlled studies in pregnant women. Tranexamic acid does cross the placenta and appears in cord blood at concentrations approximately equivalent to the maternal concentration. Reproductive studies in animals have shown no evidence of impaired fertility or harm to the fetus due to tranexamic acid. However, because animal reproductive studies are not always predictive of human response, use tranexamic acid during pregnancy only if clearly needed.

Use tranexamic acid with caution during breast-feeding and only if clearly needed. Tranexamic acid is excreted into human milk at a concentration approximately a hundredth of the corresponding serum concentration. An international consensus panel recommends against using tranexamic acid during breast-feeding in patients with hereditary angioedema caused by C1 inhibitor deficiency.

Niacinamide

Since niacin is an essential nutrient, one would expect it to be safe when administered during pregnancy at doses meeting the recommended daily allowance (RDA). Niacin is categorized as pregnancy category A under these conditions. However, when used in doses greater than the RDA for dyslipidemia, or when used parenterally for the treatment of pellagra, niacin is categorized as pregnancy category C. Most manufacturers recommend against the use of niacin in dosages greater than the RDA during pregnancy. The potential benefits of high-dose niacin therapy should be weighed against risks, since toxicological studies have not been performed.

Tranexamic Acid

There are no adequate or well-controlled studies in pregnant women. Tranexamic acid does cross the placenta and appears in cord blood at concentrations approximately equivalent to the maternal concentration. Reproductive studies in animals have shown no evidence of impaired fertility or harm to the fetus due to tranexamic acid. However, because animal reproductive studies are not always predictive of human response, use tranexamic acid during pregnancy only if clearly needed.

Niacinamide

According to a manufacturer of niacin (Niaspan), although no studies have been conducted in nursing mothers, excretion into human milk is expected. The manufacturer recommends the discontinuation of nursing or the drug due to serious adverse reactions that may occur in nursing infants from lipid-altering doses of nicotinic acid. Niacin, in the form of niacinamide, is excreted in breast milk in proportion to maternal intake. Niacin supplementation is only needed in those lactating women who do not have adequate dietary intake. The Recommended Daily Allowance (RDA) of the National Academy of Science for niacin during lactation is 20 mg. There are no safety data regarding the use of nicotinic acid in doses above the RDA during breast-feeding. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

Tranexamic Acid

Use tranexamic acid with caution during breast-feeding and only if clearly needed. Tranexamic acid is excreted into human milk at a concentration approximately a hundredth of the corresponding serum concentration. An international consensus panel recommends against using tranexamic acid during breast-feeding in patients with hereditary angioedema caused by C1 inhibitor deficiency.

Niacinamide

Niacin (nicotinic acid), when administered in doses equivalent to the RDA, is generally nontoxic. Niacinamide also rarely causes adverse reactions. Larger doses of nicotinic acid (i.e., >= 1 g/day PO), can cause adverse reactions more frequently. Differences in adverse reaction profiles can be explained by the fact that nicotinic acid has pharmacologic properties that are different from niacinamide.

Peripheral vasodilation is a well-known adverse reaction to niacin. It is characterized by flushing; warmth; and burning or tingling of the skin, especially in the face, neck, and chest. Hypotension can be caused by this vasodilation. Patients should avoid sudden changes in posture to prevent symptomatic or orthostatic hypotension. Dizziness and/or headache, including migraine, can occur. Cutaneous flushing is more likely to occur with immediate-release preparations as opposed to sustained-release ones and also increases in incidence with higher doses. Following 4-weeks of maintenance therapy of 1500 mg daily, patients receiving immediate release niacin averaged 8.6 flushing events compared to 1.9 events in the Niaspan group. In placebo-controlled studies of Niaspan, flushing occurred in 55—69% of patients compared to 19% of patients receiving placebo. Flushing was described as the reason for discontinuing therapy for 6% of patients receiving Niaspan in pivotal studies. These reactions usually improve after the initial 2 weeks of therapy. Some patients develop generalized pruritus as a result of peripheral flushing. In placebo controlled trials, pruritus was reported in 0—8% of patients receiving Niaspan compared to 2% of patients taking placebo. Rash (unspecified) was reported in 0—5% of patients in the Niaspan group compared to no patients in the placebo group. Patients should avoid ethanol or hot drinks that can precipitate flushing. Flushing can be minimized by taking niacin with meals, using low initial doses, and increasing doses gradually. If necessary, taking one aspirin (e.g., 325 mg) 30 minutes before each dose can help prevent or reduce flushing. Spontaneous reports with niacin suggest that flushing may also be accompanied by symptoms of dizziness or syncope, sinus tachycardia, palpitations, atrial fibrillation, dyspnea, diaphoresis, chills, edema, or exacerbations of angina. On rare occasions, cardiac arrhythmias or syncope has occurred. Hypersensitivity or anaphylactoid reactions have been reported rarely during niacin therapy; episodes have included one or more of the following features: anaphylaxis, angioedema, urticaria, flushing, dyspnea, tongue edema, laryngeal edema, face edema, peripheral edema, laryngospasm, maculopapular rash, and vesiculobullous rash (vesicular rash, bullous rash).

Niacin can produce a variety of GI effects, such as nausea/vomiting, abdominal pain, diarrhea, bloating, dyspepsia, or flatulence, when taken in large doses. Eructation and peptic ulcer has been reported with post-marketing experience of Niaspan. Compared to placebo, diarrhea was reported in 7—14% (vs. 13%), nausea in 4—11% (vs. 7%), and vomiting in 0—9% (vs. 4%) of patients receiving Niaspan. These effects are attributed to increased GI motility and may disappear after the first 2 weeks of therapy. Administering niacin with meals can reduce these adverse reactions.

Jaundice can result from chronic liver damage caused by niacin. It has been shown that elevated hepatic enzymes occur more frequently with some sustained-release niacin than with immediate-release products. However, in a study of 245 patients receiving Niaspan (doses ranging from 500—3000 mg/day for a mean of 17 weeks) no patients with normal serum transaminases at baseline experienced elevations to > 3x the upper limit of normal. Sustained-release products have been associated with post-marketing reports of hepatitis and jaundice, including Niaspan. Regular liver-function tests should be performed periodically. The changes in liver function induced by niacin are typically reversible with drug discontinuation. However, rare cases of fulminant hepatic necrosis and hepatic failure have been reported. Some cases have occurred after the substitution of sustained-release dosage forms for immediate-release products at directly equivalent doses; these dosage forms are not bioequivalent. Dosage titration schedules must be observed for any patient switched to a sustained-release niacin product, even if the patient was previously taking immediate-release therapy.

Niacin interferes with glucose metabolism and can result in hyperglycemia. This effect is dose related. During clinical anti-lipemic trials, increases in fasting blood glucose above normal occurred frequently (e.g., 50%) during niacin therapy. Some patients have required drug discontinuation due to hyperglycemia or exacerbation of diabetes. In the AIM-HIGH trial of patients with stable cardiovascular disease, the incidence of hyperglycemia (6.4% vs. 4.5%) and diabetes mellitus (3.6% vs. 2.2%) was higher in niacin plus simvastatin-treated patients compared to the simvastatin plus placebo group. Close blood glucose monitoring is advised for diabetic or potentially diabetic patients during treatment with niacin; adjustment of diet and/or antidiabetic therapy may be necessary.

Niacin, especially in high doses, can cause hyperuricemia. Gout has been reported in post-marketing surveillance of Niaspan. Therefore, patients predisposed to gout should be treated with caution.

Niacin, especially in high doses (>= 2 g/day PO), can cause hypophosphatemia (mean decrease 13%). Serum phosphorus concentrations should be monitored periodically in patients at risk for hypophosphatemia.

Nicotinic acid (niacin) occasionally causes slight decreases in platelet counts (mean reduction 11%) or increased prothrombin times (mean increase 4%), especially in high doses (>= 2 g/day PO). Rarely do these reactions result in coagulopathy or thrombocytopenia, but clinically significant effects might occur in patients with other risk factors or who are predisposed to these conditions.

Asthenia, nervousness, insomnia, and paresthesias have been reported during niacin therapy. Rare cases of rhabdomyolysis have been reported in patients taking niacin (nicotinic acid) in doses >=1 g/day PO and HMG-CoA reductase inhibitors (i.e., ‘statins’) concurrently. In the AIM-HIGH trial, 4 cases (0.2%) of rhabdomyolysis were reported in the niacin; simvastatin group compared with 1 case in the simvastatin plus placebo group. Rhabdomyolysis may present as myopathy (myalgia, myasthenia, muscle cramps, muscle weakness, muscle tenderness, fatigue), elevations in creatinine phosphokinase (CPK), or renal dysfunction (renal tubular obstruction). Toxicity to the skeletal muscle occurs infrequently but can be a serious adverse reaction. This toxicity appears to be reversible after discontinuation of therapy.

Niacin also has been associated with a variety of ophthalmic adverse effects including blurred vision and macular edema.

Although uncommon, niacin may be associated with skin hyperpigmentation or acanthosis nigricans. Dry skin (xerosis) also has been reported during post-marketing surveillance of Niaspan.

During clinical trials, increased cough was reported in <2—8% (vs. 6%) of patients receiving Niaspan compared to placebo.

Tranexamic Acid

Headache (50.4% vs. 46.8%) and migraine (6% vs. 5.8%) were reported more frequently in patients receiving oral tranexamic acid compared to placebo during clinical trials. Seizures have been reported with injectable tranexamic acid use, particularly in patients receiving tranexamic acid during cardiovascular surgery (a setting in which use is not FDA-approved and which uses doses up to 10-fold higher than the recommended human dose) and in those inadvertently given tranexamic acid into the neuraxial system. Closely monitor patients during surgery. Consider EEG monitoring in patients with a seizure disorder or history of seizures, or in those who experience myoclonic movements, twitching, or show evidence of focal seizures. Discontinue tranexamic acid if seizures occur.

Nasal and sinus symptoms (25.4% vs. 17.3%) were reported more frequently in patients receiving oral tranexamic acid compared to placebo during clinical trials. These symptoms were defined as sinus, respiratory tract, and nasal congestion, sinusitis, acute sinusitis, sinus headache, allergic sinusitis and sinus pain, and multiple and seasonal allergies.

Fatigue (5.2% vs. 4.3%) and anemia (5.6% vs. 3.6%) were reported more frequently in patients receiving oral tranexamic acid compared to placebo during clinical trials. Dizziness also has been identified from postmarketing surveillance and may occur with either dosage form.

Abdominal pain (19.8% vs. 18%) was reported more frequently in patients receiving oral tranexamic acid compared to placebo during clinical trials. Gastrointestinal disturbances (i.e., nausea, vomiting, diarrhea) may occur, but subside when the dosage is reduced.

Back pain (20.7% vs. 15.1%), musculoskeletal pain (11.2% vs. 2.9%) including musculoskeletal discomfort and myalgia, arthralgia (6.9% vs. 5%) including joint stiffness and swelling, and overall muscle cramps and spasms (6.5% vs. 5.8%) were reported more frequently in patients receiving oral tranexamic acid compared to placebo during clinical trials.

Hypotension has been reported when the injectable formulation of tranexamic acid is administered too rapidly. To avoid hypotension, do not administer faster than 100 mg/minute.

Hypersensitivity reactions including anaphylaxis or anaphylactoid reactions and allergic skin reactions may occur with tranexamic acid use. During clinical trials of oral tranexamic acid, a patient experienced a severe allergic reaction including dyspnea, tightening of throat, and facial flushing that required emergency medical treatment. A case of anaphylactic shock, involving a patient who received an intravenous bolus of tranexamic acid, has also been reported in the literature. Discontinue tranexamic acid if a serious reaction occurs, provide appropriate medical management, and do not restart treatment. Allergic dermatitis (rash) has been reported with postmarketing surveillance.

Retinal venous and arterial occlusions have been reported with tranexamic acid use. Discontinue tranexamic acid immediately if visual or ocular symptoms occur and refer the patient to an ophthalmologist for a complete ophthalmological evaluation, including dilated retinal examination. Ligneous conjunctivitis, resolving after discontinuation of therapy, also has been reported in patients taking oral tranexamic acid. Impaired color vision (dyschromatopsia) and other visual impairment have been reported during postmarketing use. Visual abnormalities, often poorly characterized, are the most frequently reported postmarketing adverse reactions with injectable tranexamic acid use in Sweden. In patients who are to be treated continually for more than several days with intravenous tranexamic acid, obtain an ophthalmological examination including visual acuity, color vision, eye-ground, and visual field before initiation and at regular intervals during treatment. Discontinue tranexamic acid if a visual disturbance is seen during examination.

Venous or arterial thrombosis or thromboembolism including deep vein thrombosis, pulmonary embolism, cerebral thrombosis, acute renal cortical necrosis, and central retinal artery and vein obstruction (e.g., retinal thrombosis) have been rarely reported during postmarketing surveillance of tranexamic acid.

Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.

1.Niaspan (niacin extended-release) tablet package insert. North Chicago, IL: Abbott Laboratories; 2015 Apr.
2.HPS2-THRIVE Collaborative Group. Effects of extended-release niacin with laropiprant in high-risk patients. N Engl J Med 2014;371:203-12.
3.Taylor AJ, Villines TC, Stanck EJ, et al. Extended-release niacin or ezetimibe and carotid intima-media thickness. N Engl J Med 2009. Epub ahead of print, doi:10.1056/NEJMoa907569.
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