Telmisartan and amlodipine

7 DRUG INTERACTIONS NSAIDS: Increased risk of renal impairment and loss of antihypertensive effect ( 7 ) If simvastatin is co-administered with amlodipine, do not exceed doses greater than 20 mg daily of simvastatin ( 7 ) Do not co-administer aliskiren with telmisartan and amlodipine in patients with diabetes ( 7.2 )

7.1 Drug Interactions with Telmisartan and Amlodipine Tablets The pharmacokinetics of amlodipine and telmisartan are not altered when the drugs are co-administered. No drug interaction studies have been conducted with telmisartan and amlodipine tablets and other drugs, although studies have been conducted with the individual amlodipine and telmisartan components of telmisartan and amlodipine tablets, as described below:

7.2 Drug Interactions with Telmisartan Aliskiren Do not co-administer aliskiren with telmisartan and amlodipine tablets in patients with diabetes. Avoid use of aliskiren with telmisartan and amlodipine tablets in patients with renal impairment (GFR <60 mL/min). Digoxin When telmisartan was co-administered with digoxin, median increases in digoxin peak plasma concentration (49%) and in trough concentration (20%) were observed. Therefore, monitor digoxin levels when initiating, adjusting, and discontinuing telmisartan for the purpose of keeping the digoxin level within the therapeutic range.

Lithium Reversible increases in serum lithium concentrations and toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists including telmisartan. Therefore, monitor serum lithium levels during concomitant use.

Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, co-administration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists, including telmisartan, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving telmisartan and NSAID therapy.

The antihypertensive effect of angiotensin II receptor antagonists, including telmisartan may be attenuated by NSAIDs including selective COX-2 inhibitors.

7.3 Drug Interactions with Amlodipine In clinical trials, amlodipine has been safely administered with thiazide diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, long-acting nitrates, sublingual nitroglycerin, digoxin, warfarin, non-steroidal anti-inflammatory drugs, antibiotics, and oral hypoglycemic drugs. Simvastatin Co-administration of multiple doses of 10 mg of amlodipine with 80 mg simvastatin resulted in a 77% increase in exposure to simvastatin compared to simvastatin alone. Limit the dose of simvastatin in patients on amlodipine to 20 mg daily. Immunosuppressants Amlodipine may increase the systemic exposure of cyclosporine or tacrolimus when co-administered.

Frequent monitoring of trough blood levels of cyclosporin and tacrolimus and dose adjustment when appropriate is recommended. The following have no clinically relevant effects on the pharmacokinetics of amlodipine: cimetidine, grapefruit juice, magnesium and aluminum hydroxide antacid, sildenafil. Amlodipine has no clinically relevant effects on the pharmacokinetics or pharmacodynamics of the following: atorvastatin, digoxin, warfarin. CYP3A4 Inhibitors Co-administration of a 180 mg daily dose of diltiazem with 5 mg amlodipine in elderly hypertensive patients resulted in a 60% increase in amlodipine systemic exposure.

Erythromycin co-administration in healthy volunteers did not significantly change amlodipine systemic exposure. However, strong inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, ritonavir) may increase the plasma concentrations of amlodipine to a greater extent. Monitor for symptoms of hypotension and edema when amlodipine is co-administered with CYP3A4 inhibitors. CYP3A4 Inducers No information is available on the quantitative effects of CYP3A4 inducers ( e.g., carbamazepine, phenobarbital, phenytoin, fosphenytoin, primidone, rifampicin, St. John's Wort) on amlodipine. Patients should be monitored for adequate clinical effect when amlodipine is co-administered with CYP3A4 inducers.

8.1 Pregnancy Risk Summary Telmisartan and amlodipine tablets can cause fetal harm when administered to a pregnant woman. Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death (see Clinical Considerations) . Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. Studies in rats and rabbits with telmisartan showed fetotoxicity only at maternally toxic doses (see Data) .

In animal reproduction studies, there was no evidence of adverse developmental effects when pregnant rats and rabbits were treated orally with amlodipine maleate during organogenesis at doses approximately 10 and 20-times the maximum recommended human dose (MRHD), respectively. However for rats, litter size was significantly decreased (by about 50%) and the number of intrauterine deaths was significantly increased (about 5-fold). Amlodipine has been shown to prolong both the gestation period and the duration of labor in rats at this dose ( see Data ). When pregnancy is detected, discontinue telmisartan and amlodipine tablets as soon as possible.

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major malformations and miscarriage in clinically recognized pregnancies is 2% to 4%, and 15% to 20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk: Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, and post-partum hemorrhage).

Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Pregnant women with hypertension should be carefully monitored and managed accordingly. Fetal/Neonatal adverse reactions: Use of drugs that act on the RAS in the second and third trimesters of pregnancy can result in the following: oligohydramnios, reduced fetal renal function leading to anuria and renal failure, fetal lung hypoplasia, skeletal deformations, including skull hypoplasia, hypotension, and death. In the unusual case that there is no appropriate alternative to therapy with drugs affecting the…

8.2 Lactation Risk Summary There is no information regarding the presence of telmisartan and amlodipine tablets or telmisartan in human milk, the effects on the breastfed infant, or the effects on milk production. Limited published studies report that amlodipine is present in human milk. However, there is insufficient information to determine the effects of amlodipine on the breastfed infant. There is no available information on the effects of amlodipine on milk production. Telmisartan is present in the milk of lactating rats (see Data) .

Because of the potential for serious adverse reactions in the breastfed infant including hypotension, hyperkalemia and renal impairment, advise a nursing woman not to breastfeed during treatment with telmisartan and amlodipine tablets. Data: Telmisartan was present in the milk of lactating rats at concentrations 1.5 to 2 times those found in plasma from 4 to 8 hours after administration.