Oral terbinafine is not recommended for use in patients with chronic or active liver disease. Terbinafine may be hepatotoxic. Rare cases of cholestatic hepatitis and liver failure, some resulting in liver transplant or death, have been reported during treatment of various dermatologic conditions in patients with and without preexisting liver disease. Although a causal relationship has not been established, the severity of hepatic events and/or their outcome may be worse in patients with active or chronic liver disease.
Isolated cases of severe neutropenia have been reported in patients administered oral terbinafine. A causal relationship has not been established, although the neutropenia resolved following discontinuation of terbinafine with or without supportive care. Therapy with terbinafine should be administered cautiously in patients with preexisting neutropenia. It may be appropriate to monitor blood counts more frequently during terbinafine therapy. If secondary infection occurs and the neutrophil count is <= 1000 cells/mm3, terbinafine should be discontinued and supportive management initiated.
Transient decreases in absolute lymphocyte counts have been reported with oral terbinafine during clinical trials. The clinical significance of these decreases is unknown. Monitoring of complete blood counts may be appropriate in patients with known or suspected immunodeficiency receiving terbinafine for greater than six weeks.
The use of oral terbinafine in patients with renal impairment (CrCl <= 50 mL/min) has not been adequately studied and is, therefore, not recommended. Terbinafine metabolites are primarily eliminated by the kidney. The clinical significance of possible metabolite accumulation due to decreased clearance is unknown.
poniedziałek, 5 listopada 2012
Lamisil side effects
Get emergency medical help if you have any of these signs of an allergic reaction while taking terbinafine (the active ingredient contained in Lamisil) hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Some people taking terbinafine have developed severe liver damage leading to liver transplant or death. It is not clear whether terbinafine actually caused the liver damage in these patients. In most cases, the patient had a serious medical condition before taking terbinafine.
Call your doctor at once if you have symptoms of liver damage, such as nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes). These events can occur whether or not you have ever had liver problems before.
Stop taking terbinafine and call your doctor at once if you have a serious side effect such as:
fever, chills, body aches, flu symptoms, sores in your mouth and throat;
joint pain or swelling, swollen glands, patchy skin color, or a butterfly-shaped skin rash over your cheeks and nose;
changes in mood or behavior;
hearing problems;
weight loss due to taste changes;
raised, silvery flaking of the skin; or
severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Less serious side effects of terbinafine may include:
upset stomach, gas, diarrhea, mild nausea or stomach pain;
headache, dizziness or spinning sensation;
mild skin rash or itching; or
unusual or unpleasant taste in your mouth.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
Some people taking terbinafine have developed severe liver damage leading to liver transplant or death. It is not clear whether terbinafine actually caused the liver damage in these patients. In most cases, the patient had a serious medical condition before taking terbinafine.
Call your doctor at once if you have symptoms of liver damage, such as nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes). These events can occur whether or not you have ever had liver problems before.
Stop taking terbinafine and call your doctor at once if you have a serious side effect such as:
fever, chills, body aches, flu symptoms, sores in your mouth and throat;
joint pain or swelling, swollen glands, patchy skin color, or a butterfly-shaped skin rash over your cheeks and nose;
changes in mood or behavior;
hearing problems;
weight loss due to taste changes;
raised, silvery flaking of the skin; or
severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Less serious side effects of terbinafine may include:
upset stomach, gas, diarrhea, mild nausea or stomach pain;
headache, dizziness or spinning sensation;
mild skin rash or itching; or
unusual or unpleasant taste in your mouth.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
Lamisil PATIENT COUNSELING INFORMATION
Patients taking Lamisil Tablets should receive the following information and instructions:
• Patients should take one 250 mg tablet once daily for 6 weeks for treatment of fingernail onychomycosis or once daily for 12 weeks for treatment of toenail onychomycosis. The optimal clinical effect is seen some months after mycological cure and cessation of treatment due to the time period required for outgrowth of healthy nail.
• Patients should be advised to immediately report to their physician any symptoms of persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine or pale stools. Lamisil Tablets treatment should be discontinued.
• Patients should be advised to report to their physician any signs of taste disturbance, smell disturbance and/or depressive symptoms. Lamisil Tablets treatment should be discontinued.
• Patients should be advised to immediately report to their physician or get emergency help if they experience any of the following symptoms: hives, mouth sores, blistering and peeling of skin, swelling of face, lips, tongue, or throat, difficulty swallowing or breathing. Lamisil Tablets treatment should be discontinued.
• Patients should be advised to report to their physician any symptoms of new onset or worsening lupus erythematosus. Symptoms can include erythema, scaling, loss of pigment, and unusual photosensitivity that can result in a rash. Lamisil treatment should be discontinued.
• Photosensitivity reactions have been reported with the use of Lamisil. Patients should be advised to minimize exposure to natural and artificial sunlight (tanning beds or UVA/B treatment) while using Lamisil.
• Measurement of serum transaminases (ALT and AST) is advised for all patients before taking Lamisil Tablets.
• Patients should be advised that if they forget to take Lamisil Tablets, to take their tablets as soon as they remember, unless it is less than four hours before the next dose is due. Patients should also be advised that if they take too many Lamisil Tablets they should call their physician.
• Patients should take one 250 mg tablet once daily for 6 weeks for treatment of fingernail onychomycosis or once daily for 12 weeks for treatment of toenail onychomycosis. The optimal clinical effect is seen some months after mycological cure and cessation of treatment due to the time period required for outgrowth of healthy nail.
• Patients should be advised to immediately report to their physician any symptoms of persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine or pale stools. Lamisil Tablets treatment should be discontinued.
• Patients should be advised to report to their physician any signs of taste disturbance, smell disturbance and/or depressive symptoms. Lamisil Tablets treatment should be discontinued.
• Patients should be advised to immediately report to their physician or get emergency help if they experience any of the following symptoms: hives, mouth sores, blistering and peeling of skin, swelling of face, lips, tongue, or throat, difficulty swallowing or breathing. Lamisil Tablets treatment should be discontinued.
• Patients should be advised to report to their physician any symptoms of new onset or worsening lupus erythematosus. Symptoms can include erythema, scaling, loss of pigment, and unusual photosensitivity that can result in a rash. Lamisil treatment should be discontinued.
• Photosensitivity reactions have been reported with the use of Lamisil. Patients should be advised to minimize exposure to natural and artificial sunlight (tanning beds or UVA/B treatment) while using Lamisil.
• Measurement of serum transaminases (ALT and AST) is advised for all patients before taking Lamisil Tablets.
• Patients should be advised that if they forget to take Lamisil Tablets, to take their tablets as soon as they remember, unless it is less than four hours before the next dose is due. Patients should also be advised that if they take too many Lamisil Tablets they should call their physician.
Lamisil Pharmacokinetics
Following oral administration, terbinafine is well absorbed (>70%) and the bioavailability of Lamisil Tablets as a result of first-pass metabolism is approximately 40%. Peak plasma concentrations of 1 µg/mL appear within 2 hours after a single 250 mg dose; the AUC (area under the curve) is approximately 4.56 µg.h/mL. An increase in the AUC of terbinafine of less than 20% is observed when Lamisil Tablets are administered with food.
In plasma, terbinafine is >99% bound to plasma proteins and there are no specific binding sites. At steady-state, in comparison to a single dose, the peak concentration of terbinafine is 25% higher and plasma AUC increases by a factor of 2.5; the increase in plasma AUC is consistent with an effective half-life of ~36 hours. Terbinafine is distributed to the sebum and skin. A terminal half-life of 200-400 hours may represent the slow elimination of terbinafine from tissues such as skin and adipose. Prior to excretion, terbinafine is extensively metabolized by at least seven CYP isoenzymes with major contributions from CYP2C9, CYP1A2, CYP3A4, CYP2C8 and CYP2C19. No metabolites have been identified that have antifungal activity similar to terbinafine. Approximately 70% of the administered dose is eliminated in the urine.
In patients with renal impairment (creatinine clearance <50 mL/min) or hepatic cirrhosis, the clearance of terbinafine is decreased by approximately 50% compared to normal volunteers. No effect of gender on the blood levels of terbinafine was detected in clinical trials. No clinically relevant age-dependent changes in steady-state plasma concentrations of terbinafine have been reported.
In plasma, terbinafine is >99% bound to plasma proteins and there are no specific binding sites. At steady-state, in comparison to a single dose, the peak concentration of terbinafine is 25% higher and plasma AUC increases by a factor of 2.5; the increase in plasma AUC is consistent with an effective half-life of ~36 hours. Terbinafine is distributed to the sebum and skin. A terminal half-life of 200-400 hours may represent the slow elimination of terbinafine from tissues such as skin and adipose. Prior to excretion, terbinafine is extensively metabolized by at least seven CYP isoenzymes with major contributions from CYP2C9, CYP1A2, CYP3A4, CYP2C8 and CYP2C19. No metabolites have been identified that have antifungal activity similar to terbinafine. Approximately 70% of the administered dose is eliminated in the urine.
In patients with renal impairment (creatinine clearance <50 mL/min) or hepatic cirrhosis, the clearance of terbinafine is decreased by approximately 50% compared to normal volunteers. No effect of gender on the blood levels of terbinafine was detected in clinical trials. No clinically relevant age-dependent changes in steady-state plasma concentrations of terbinafine have been reported.
Lamisil drug interaction
In vivo studies have shown that terbinafine is an inhibitor of the CYP450 2D6 isozyme. Drugs predominantly metabolized by the CYP450 2D6 isozyme include the following drug classes: tricyclic antidepressants, selective serotonin reuptake inhibitors, beta-blockers, antiarrhythmics class 1C (e.g., flecainide and propafenone) and monoamine oxidase inhibitors Type B. Coadministration of Lamisil should be done with careful monitoring and may require a reduction in dose of the 2D6-metabolized drug. In a study to assess the effects of terbinafine on desipramine in healthy volunteers characterized as normal metabolizers, the administration of terbinafine resulted in a 2-fold increase in Cmax and a 5-fold increase in AUC. In this study, these effects were shown to persist at the last observation at 4 weeks after discontinuation of Lamisil Tablets. In studies in healthy subjects characterized as extensive metabolizers of dextromethorphan (antitussive drug and CYP2D6 probe substrate), terbinafine increases the dextromethorphan/dextrorphan metabolite ratio in urine by 16- to 97-fold on average. Thus, terbinafine may convert extensive CYP2D6 metabolizers to poor metabolizer status.
In vitro studies with human liver microsomes showed that terbinafine does not inhibit the metabolism of tolbutamide, ethinylestradiol, ethoxycoumarin, cyclosporine, cisapride and fluvastatin. In vivo drug-drug interaction studies conducted in healthy volunteer subjects showed that terbinafine does not affect the clearance of antipyrine or digoxin. Terbinafine decreases the clearance of caffeine by 19%. Terbinafine increases the clearance of cyclosporine by 15%.
The influence of terbinafine on the pharmacokinetics of fluconazole, cotrimoxazole (trimethoprim and sulfamethoxazole), zidovudine or theophylline was not considered to be clinically significant.
Co-administration of a single dose of fluconazole (100mg) with a single dose of terbinafine resulted in a 52% and 69% increase in terbinafine Cmax and AUC, respectively. Fluconazole is an inhibitor of CYP2C9 and CYP3A enzymes. Based on this finding, it is likely that other inhibitors of both CYP2C9 and CYP3A4 (e.g., ketoconazole, amiodarone) may also lead to a substantial increase in the systemic exposure (Cmax and AUC) of terbinafine when concomitantly administered.
There have been spontaneous reports of increase or decrease in prothrombin times in patients concomitantly taking oral terbinafine and warfarin, however, a causal relationship between Lamisil Tablets and these changes has not been established.
Terbinafine clearance is increased 100% by rifampin, a CYP450 enzyme inducer, and decreased 33% by cimetidine, a CYP450 enzyme inhibitor. Terbinafine clearance is unaffected by cyclosporine. There is no information available from adequate drug-drug interaction studies with the following classes of drugs: oral contraceptives, hormone replacement therapies, hypoglycemics, phenytoins, thiazide diuretics, and calcium channel blockers.
In vitro studies with human liver microsomes showed that terbinafine does not inhibit the metabolism of tolbutamide, ethinylestradiol, ethoxycoumarin, cyclosporine, cisapride and fluvastatin. In vivo drug-drug interaction studies conducted in healthy volunteer subjects showed that terbinafine does not affect the clearance of antipyrine or digoxin. Terbinafine decreases the clearance of caffeine by 19%. Terbinafine increases the clearance of cyclosporine by 15%.
The influence of terbinafine on the pharmacokinetics of fluconazole, cotrimoxazole (trimethoprim and sulfamethoxazole), zidovudine or theophylline was not considered to be clinically significant.
Co-administration of a single dose of fluconazole (100mg) with a single dose of terbinafine resulted in a 52% and 69% increase in terbinafine Cmax and AUC, respectively. Fluconazole is an inhibitor of CYP2C9 and CYP3A enzymes. Based on this finding, it is likely that other inhibitors of both CYP2C9 and CYP3A4 (e.g., ketoconazole, amiodarone) may also lead to a substantial increase in the systemic exposure (Cmax and AUC) of terbinafine when concomitantly administered.
There have been spontaneous reports of increase or decrease in prothrombin times in patients concomitantly taking oral terbinafine and warfarin, however, a causal relationship between Lamisil Tablets and these changes has not been established.
Terbinafine clearance is increased 100% by rifampin, a CYP450 enzyme inducer, and decreased 33% by cimetidine, a CYP450 enzyme inhibitor. Terbinafine clearance is unaffected by cyclosporine. There is no information available from adequate drug-drug interaction studies with the following classes of drugs: oral contraceptives, hormone replacement therapies, hypoglycemics, phenytoins, thiazide diuretics, and calcium channel blockers.
Lamisil Adverse Reactions
Because clinical trials are conducted under widely varying conditions, adverse reaction rates in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The most frequently reported adverse events observed in the three US/Canadian placebo-controlled trials are listed in the table below. The adverse events reported encompass gastrointestinal symptoms (including diarrhea, dyspepsia, and abdominal pain), liver test abnormalities, rashes, urticaria, pruritus, and taste disturbances. Changes in the ocular lens and retina have been reported following the use of Lamisil Tablets in controlled trials. The clinical significance of these changes is unknown. In general, the adverse events were mild, transient, and did not lead to discontinuation from study participation.
The following adverse events have been identified during post-approval use of Lamisil. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Adverse events, based on worldwide experience with Lamisil Tablets use, include: idiosyncratic and symptomatic hepatic injury and more rarely, cases of liver failure, some leading to death or liver transplant, serious skin reactions (e.g., Stevens-Johnson Syndrome and toxic epidermal necrolysis), severe neutropenia, thrombocytopenia, agranulocytosis, pancytopenia, anemia, angioedema, and allergic reactions (including anaphylaxis) [see Warnings and Precautions (5.1, 5.5 , and 5.6)].
Psoriasiform eruptions or exacerbation of psoriasis, acute generalized exanthematous pustulosis and precipitation and exacerbation of cutaneous and systemic lupus erythematosus have been reported in patients taking Lamisil [see Warnings and Precautions (5.7)].
Cases of taste disturbance, including taste loss, have been reported with the use of Lamisil Tablets. It can be severe enough to result in decreased food intake, weight loss, and depressive symptoms [see Warnings and Precautions (5.2)]. Depressive symptoms independent of taste disturbance have been reported with use of Lamisil Tablets. In some cases, depressive symptoms have been reported to subside with discontinuance of therapy and to recur with reinstitution of therapy [see Warnings and Precautions (5.4)]. Cases of smell disturbance, including smell loss, have been reported with the use of Lamisil Tablets [see Warnings and Precautions (5.3)].
Other adverse reactions which have been reported include malaise, fatigue, vomiting, arthralgia, myalgia, rhabdomyolysis, reduced visual acuity, visual field defect, hair loss, serum sickness-like reaction, vasculitis, pancreatitis, influenza-like illness, pyrexia, increased blood creatine phosphokinase, photosensitivity reactions, tinnitus, hearing impairment and vertigo.
Altered prothrombin time (prolongation and reduction) in patients concomitantly treated with warfarin has been reported.
The most frequently reported adverse events observed in the three US/Canadian placebo-controlled trials are listed in the table below. The adverse events reported encompass gastrointestinal symptoms (including diarrhea, dyspepsia, and abdominal pain), liver test abnormalities, rashes, urticaria, pruritus, and taste disturbances. Changes in the ocular lens and retina have been reported following the use of Lamisil Tablets in controlled trials. The clinical significance of these changes is unknown. In general, the adverse events were mild, transient, and did not lead to discontinuation from study participation.
The following adverse events have been identified during post-approval use of Lamisil. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Adverse events, based on worldwide experience with Lamisil Tablets use, include: idiosyncratic and symptomatic hepatic injury and more rarely, cases of liver failure, some leading to death or liver transplant, serious skin reactions (e.g., Stevens-Johnson Syndrome and toxic epidermal necrolysis), severe neutropenia, thrombocytopenia, agranulocytosis, pancytopenia, anemia, angioedema, and allergic reactions (including anaphylaxis) [see Warnings and Precautions (5.1, 5.5 , and 5.6)].
Psoriasiform eruptions or exacerbation of psoriasis, acute generalized exanthematous pustulosis and precipitation and exacerbation of cutaneous and systemic lupus erythematosus have been reported in patients taking Lamisil [see Warnings and Precautions (5.7)].
Cases of taste disturbance, including taste loss, have been reported with the use of Lamisil Tablets. It can be severe enough to result in decreased food intake, weight loss, and depressive symptoms [see Warnings and Precautions (5.2)]. Depressive symptoms independent of taste disturbance have been reported with use of Lamisil Tablets. In some cases, depressive symptoms have been reported to subside with discontinuance of therapy and to recur with reinstitution of therapy [see Warnings and Precautions (5.4)]. Cases of smell disturbance, including smell loss, have been reported with the use of Lamisil Tablets [see Warnings and Precautions (5.3)].
Other adverse reactions which have been reported include malaise, fatigue, vomiting, arthralgia, myalgia, rhabdomyolysis, reduced visual acuity, visual field defect, hair loss, serum sickness-like reaction, vasculitis, pancreatitis, influenza-like illness, pyrexia, increased blood creatine phosphokinase, photosensitivity reactions, tinnitus, hearing impairment and vertigo.
Altered prothrombin time (prolongation and reduction) in patients concomitantly treated with warfarin has been reported.
Lamisil warnings
Depressive symptoms have occurred during postmarketing use of terbinafine. Prescribers should be alert to depressive symptoms, and patients should be instructed to report depressive symptoms to their physician.
Transient decreases in absolute lymphocyte counts (ALC) have been observed in controlled clinical trials. In placebo-controlled trials, 8/465 Lamisil-treated patients (1.7%) and 3/137 placebo-treated patients (2.2%) had decreases in ALC to below 1000/mm3 on two or more occasions. In patients with known or suspected immunodeficiency, physicians should consider monitoring complete blood counts if treatment continues for more than six weeks. Cases of severe neutropenia have been reported. These were reversible upon discontinuation of Lamisil, with or without supportive therapy. If clinical signs and symptoms suggestive of secondary infection occur, a complete blood count should be obtained. If the neutrophil count is <1,000 cells/mm3, Lamisil should be discontinued and supportive management started.
There have been postmarketing reports of serious skin reactions (e.g., Stevens-Johnson Syndrome and toxic epidermal necrolysis). If progressive skin rash occurs, treatment with Lamisil Tablets should be discontinued.
During post-marketing experience, precipitation and exacerbation of cutaneous and systemic lupus erythematosus have been reported in patients taking Lamisil Tablets. Lamisil Tablets should be discontinued in patients with clinical signs and symptoms suggestive of lupus erythematosus.
Measurement of serum transaminases (ALT and AST) is advised for all patients before taking Lamisil Tablets.
Transient decreases in absolute lymphocyte counts (ALC) have been observed in controlled clinical trials. In placebo-controlled trials, 8/465 Lamisil-treated patients (1.7%) and 3/137 placebo-treated patients (2.2%) had decreases in ALC to below 1000/mm3 on two or more occasions. In patients with known or suspected immunodeficiency, physicians should consider monitoring complete blood counts if treatment continues for more than six weeks. Cases of severe neutropenia have been reported. These were reversible upon discontinuation of Lamisil, with or without supportive therapy. If clinical signs and symptoms suggestive of secondary infection occur, a complete blood count should be obtained. If the neutrophil count is <1,000 cells/mm3, Lamisil should be discontinued and supportive management started.
There have been postmarketing reports of serious skin reactions (e.g., Stevens-Johnson Syndrome and toxic epidermal necrolysis). If progressive skin rash occurs, treatment with Lamisil Tablets should be discontinued.
During post-marketing experience, precipitation and exacerbation of cutaneous and systemic lupus erythematosus have been reported in patients taking Lamisil Tablets. Lamisil Tablets should be discontinued in patients with clinical signs and symptoms suggestive of lupus erythematosus.
Measurement of serum transaminases (ALT and AST) is advised for all patients before taking Lamisil Tablets.
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