Drugs to Treat High Blood Pressure
Robin Brain
December 04, 2008
Hydralazine
The anti-hypertensive effects of this drug has been known since 1950s but it fell into disrepute because it caused reflex increase in the heart rate (palpitation) and had a tendency to cause systemic lupus syndrome (a kind of an allergic manifestation) to dependent allergic manifestation. It is one of the safest drugs available for the treatment of high blood pressure in pregnancy.
Dosage: It is given in a small dose of20 mg twice daily and the doses are gradually increased in order to avoid headache and flushing which are prominent at the start of the therapy. It may be combined with propranolol.
Adverse Effects: Hydralazine causes headache, flushing, palpitation, and peripheral edema. Most of these adverse effects are counteracted by thiazide diuretics and propranolol which may have, already been given to a patient before starting therapy with this drug. The systemic lupus reaction is rarely seen when the daily doses of hydralazine are kept below 200 mg.
Precautions
Some people metabolize hydralazine slowly (slow acetylators) due to a deficient genetic make-up. For this reason the does should be increased slowly. This minimizes the adverse effects of headache and flushing.
Hydralazine should not be taken by patients of angina or with any history of heart disease.
Minoxidil (Mintop 2% lotion)
This dilates the blood vessels and reduces the blood pressure. It is more potent and longer acting than hydralazine and is useful when other drugs fail. It increases hair growth and has been used for treatment of baldness as 2% lotion. It is used only in severe uncontrollable hypertension.
Calcium Channel Blockers (CCBs)
This group of drugs decrease inward movement of calcium ion in cells of heart and blood vessels. Therefore, heart rate and pumping action of heart are reduced directly by drugs such as diltiazem and verapamil.
Nifedipine, amlodipine and other drugs have negligible depressant effect on heart and increase heart rate.
These drugs are increasingly used in mild, moderate and severe hypertension. The usual dosage forms of Nifedipine are NICARDIA, CALCIGARD, CARDULES 5 mg, 10 mg tablets or capsule and longer acting CD tablets. Usual dose is 10 mg three to four times a day. A longer acting preparation can be given twice a day. It must be remembered that palpitation and flushing, can occur with nifedipine.
Verapamil (Isoptin, Calaptin 40 mg, 80 mg; Inj. 10 mg/ml)
Its usual dose is 40 to 80 mg three times a day. This is more commonly used to reduce normalize episodes of rapid heart rates.
Diltiazem (Dilzem Cardiazen 30 mg, 60 mg)
Usual dose is 30 to 60 mg three times a day. These drugs reduce pulse rate and can precipitate congestive heart failure in borderline cases. Regular heart beat may be affected.
Amlodipine (Amlodac, Amlocor 2.5 mg. 5.0 mg tablet)
It is slower acting than nifedipine so is less likely to cause tachycardia. Nowadays, it is the most commonly used drug for hypertension in a dose of 2.5 to 10 mg once a day. S-amlodipine is a newer version and roughly twice as potent as amlodipine.
Get more information on Generic Names for Prescription Drugs and Pharmaceutical Manufacturers.
The anti-hypertensive effects of this drug has been known since 1950s but it fell into disrepute because it caused reflex increase in the heart rate (palpitation) and had a tendency to cause systemic lupus syndrome (a kind of an allergic manifestation) to dependent allergic manifestation. It is one of the safest drugs available for the treatment of high blood pressure in pregnancy.
Dosage: It is given in a small dose of20 mg twice daily and the doses are gradually increased in order to avoid headache and flushing which are prominent at the start of the therapy. It may be combined with propranolol.
Adverse Effects: Hydralazine causes headache, flushing, palpitation, and peripheral edema. Most of these adverse effects are counteracted by thiazide diuretics and propranolol which may have, already been given to a patient before starting therapy with this drug. The systemic lupus reaction is rarely seen when the daily doses of hydralazine are kept below 200 mg.
Precautions
Some people metabolize hydralazine slowly (slow acetylators) due to a deficient genetic make-up. For this reason the does should be increased slowly. This minimizes the adverse effects of headache and flushing.
Hydralazine should not be taken by patients of angina or with any history of heart disease.
Minoxidil (Mintop 2% lotion)
This dilates the blood vessels and reduces the blood pressure. It is more potent and longer acting than hydralazine and is useful when other drugs fail. It increases hair growth and has been used for treatment of baldness as 2% lotion. It is used only in severe uncontrollable hypertension.
Calcium Channel Blockers (CCBs)
This group of drugs decrease inward movement of calcium ion in cells of heart and blood vessels. Therefore, heart rate and pumping action of heart are reduced directly by drugs such as diltiazem and verapamil.
Nifedipine, amlodipine and other drugs have negligible depressant effect on heart and increase heart rate.
These drugs are increasingly used in mild, moderate and severe hypertension. The usual dosage forms of Nifedipine are NICARDIA, CALCIGARD, CARDULES 5 mg, 10 mg tablets or capsule and longer acting CD tablets. Usual dose is 10 mg three to four times a day. A longer acting preparation can be given twice a day. It must be remembered that palpitation and flushing, can occur with nifedipine.
Verapamil (Isoptin, Calaptin 40 mg, 80 mg; Inj. 10 mg/ml)
Its usual dose is 40 to 80 mg three times a day. This is more commonly used to reduce normalize episodes of rapid heart rates.
Diltiazem (Dilzem Cardiazen 30 mg, 60 mg)
Usual dose is 30 to 60 mg three times a day. These drugs reduce pulse rate and can precipitate congestive heart failure in borderline cases. Regular heart beat may be affected.
Amlodipine (Amlodac, Amlocor 2.5 mg. 5.0 mg tablet)
It is slower acting than nifedipine so is less likely to cause tachycardia. Nowadays, it is the most commonly used drug for hypertension in a dose of 2.5 to 10 mg once a day. S-amlodipine is a newer version and roughly twice as potent as amlodipine.
Get more information on Generic Names for Prescription Drugs and Pharmaceutical Manufacturers.
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