Combination therapy
Amlodipine can be given as a combination therapy with a variety of medications:
Amlodipine/atorvastatin, where amlodipine is given for hypertension or CAD and atorvastatin prevents cardiovascular events, or if the person also has high cholesterol. Amlodipine/aliskiren or amlodipine/aliskiren/hydrochlorothiazide if amlodipine alone cannot reduce blood pressure. Aliskiren is a renin inhibitor, which works to reduce primary hypertension (that with no known cause) by binding to renin and preventing it from initiating the renin–angiotensin system (RAAS) pathway to increase blood pressure. Hydrochlorothiazide is a diuretic and decreases overall blood volume. Amlodipine/benazepril if either drug has failed individually, or amlodipine alone caused edema. Benazepril is an ACE inhibitor and blocks the conversion of angiotensin I to angiotensin II in the RAAS pathway. Amlodipine/celecoxib
Amlodipine/lisinopril
Amlodipine/olmesartan or amlodipine/olmesartan/hydrochlorothiazide if amlodipine is insufficient in reducing blood pressure. Olmesartan is an angiotensin II receptor antagonist and blocks part of the RAAS pathway. Amlodipine/perindopril if using amlodipine alone caused edema. Perindopril is a long-lasting ACE inhibitor. Amlodipine/telmisartan, where telmisartan is an angiotensin II receptor antagonist. Amlodipine/valsartan or amlodipine/valsartan/hydrochlorothiazide, where valsartan is an angiotensin II receptor antagonist. Contraindications
The only absolute contraindication to amlodipine is an allergy to amlodipine or any other dihydropyridines.Other situations occur, however, where amlodipine generally should not be used. In patients with cardiogenic shock, where the hearts ventricles are not able to pump enough blood, calcium channel blockers exacerbate the situation by preventing the flow of calcium ions into cardiac cells, which is required for the heart to pump.
While use in patients with aortic stenosis (narrowing of the aorta where it meets the left ventricle) since it does not inhibit the ventricles function is generally safe, it can still cause collapse in cases of severe stenosis. In unstable angina (excluding variant angina), amlodipine can cause a reflex increase in cardiac contractility (how hard the ventricles squeeze) and heart rate, which together increase the demand for oxygen by the heart itself. Patients with severe hypotension can have their low blood pressure exacerbated, and patients in heart failure can get pulmonary edema. Those with impaired liver function are unable to metabolize amlodipine to its full extent, giving it a longer half-life than typical.Amlodipines safety in pregnancy has not been established, although reproductive toxicity at high doses is known. Whether amlodipine enters the milk of breastfeeding mothers is also unknown.Those who have heart failure, or recently had a heart attack, should take amlodipine with caution. Adverse effects
Some common dose-dependent adverse effects of amlodipine include vasodilatory effects, peripheral edema, dizziness, palpitations, and flushing. Peripheral edema (fluid accumulation in the tissues) occurs at rate of 10.8% at a 10-mg dose (versus 0.6% for placebos), and is three times more likely in women than in men. It causes more dilation in the arterioles and precapillary vessels than the postcapillary vessels and venules. The increased dilation allows for more blood, which is unable to push through to the relatively constricted postcapillary venules and vessels; the pressure causes much of the plasma to move into the interstitial space.