Nifedipine belongs to a class of antihypertensive drug called calcium channel blockers. It reduces the heart’s workload by relaxing the smooth muscles and widening the lumen of the blood vessels (arteries and veins). It is used to treat hypertension or high blood pressure and angina pectoris (chest pain). The common ending for most of the calcium channel blockers is – IPINE.
Avoid grapefruit or grapefruit juice when taking nifedipine because of a possible interaction that may have dangerous effect. Be careful in changing positions since you may become dizzy especially when you stand or sit up from a lying position or if you wake up during the night. Be cautious in taking alcohol because it may further lower down the blood pressure and increase drowsiness and dizziness while taking nifedipine. Do not stop taking nifedipine without informing your doctor, you may experience a rebound of your symptoms or your condition could become worse. Do not take a double dose if you missed the usual dosage instructed by your doctor.
Special precautions: kidney disease; liver disease; another disease of the heart or blood vessels such as sick sinus syndrome, aortic stenosis, heart failure, low blood pressure, or coronary artery disease. You may not be able to take nifedipine, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.
Nifedipine is not known whether it will be harmful to an unborn baby (US FDA pregnancy category C). This medicine also passes into the breast milk. Do not take nifedipine if you are breastfeeding or if you are pregnant without informing your doctor If you are over 65 years of age, you may be more likely to experience side effects from nifedipine. Your doctor may prescribe a lower dose of this medication.
Symptoms of a nifedipine overdose include dizziness, weakness, chest pain, shortness of breath, fainting, an unusually fast or slow heartbeat, coma, slurred speech, and confusion. Seek emergency consult once you experience the above symptoms.
Serious adverse effects: allergic reaction (difficulty of breathing, closing of the throat, swelling of the lips, tongue, face or hives; fast or slow heartbeats; severe dizziness or fainting; psychosis; jaundice(yellowing of the skin or eyes); swelling of the legs and ankles. Less serious side effects are: headache, fatigue or tiredness; flushing; insomnia; vivid or abnormal dreams; nausea or constipation; increased urination.
Drug interactions: cimetidine (Tagamet, Tagamet HB); another heart medication to treat the same or another condition; erythromycin (E-Mycin and others); itraconazole (Sporanox) or ketoconazole (Nizoral); carbamazepine (Tegretol); phenytoin (Dilantin) and rifampin (Rifadin, Rimactane) or rifabutin (Mycobutin). Drugs other than those listed here may also interact with nifedipine so always inform your doctor.
Nifedipine is an antianginal drug belonging to a class of pharmacological agents, the calcium channel blockers. Nifedipine is 3,5-pyridinedicarboxylic acid, 1,4-dihydro-2, 6-dimethyl-4-(2-nitrophenyl)-,dimethyl ester, C17H18N2O6. Nifedipine is a yellow crystalline substance, practically insoluble in water but soluble in ethanol. It has a molecular weight of 346.3. Procardia XL is a trademark for nifedipine GITS. Nifedipine GITS (Gastrointestinal Therapeutic System) Tablet is formulated as a once-a-day controlled-release tablet for oral administration designed to deliver 30, 60, or 90 mg of nifedipine.
Nifedipine has the following structural formula: