Caution is required when a calcium antagonist is given to patients with A-V block of any origin. Of the calcium antagonists, only verapamil displays signiﬁcant cardiac muscle effects and other members of the group are thus used for coronary and peripheral vasodilation effects.
Side-effects and precautions with calcium antagonists. Side-effects include: hypotension; ﬂushing; headache; dizziness; nausea. Perhexiline (Pexid) displays side-effects which include: dizziness; ataxia; impotence; liver damage: peripheral neuropathy; raised intracranial pressure; loss of vision; severe weight loss. Diabetic Neuropathy Test is essential for anyone suffering from diabetes.
Nifedipine is taken orally (10 mg three times daily) as a chronic prophylactic of angina pectoris attacks. It is used in similar doses in some hypertensive patients. Nifedipine may also be taken sublingually in acute angina attacks and acute left ventricular heart failure. The capsule is opened and its contents sprinkled under the tongue.