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Indication & Dosage |
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| Oral |
| MANAGEMENT OF HYPERTENSION |
| Adult:
Monotherapy: Initially, 250 mg bid-tid for 2 days; adjust according to response not more than every 2 days. Maintenance: 0.5-2 g daily. Max: 3 g daily. Combination therapy: Initial dose should not exceed 500 mg daily in divided doses. Elderly: Initially, 125 mg bid; gradually increase according to response. Max: 2 g daily. |
| Max Dosage: 3 g daily |
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| Oral |
| MANAGEMENT OF HYPERTENSION |
| Child:
Initially, 10 mg/kg or 300 mg/m2 daily in 2-4 divided doses; increase as necessary. Max: 65 mg/kg, 2 g/m2 or 3 g daily, whichever is least.
Elderly: Initially, 125 mg bid; gradually increase according to response. Max: 2 g daily. |
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| Intravenous |
| MANAGEMENT OF HYPERTENSION |
| Adult:
As methyldopate hydrochloride: 250-500 mg in 100 ml of 5% glucose injected over 30-60 min every 6 hr. Max: 1 g every 6 hr. |
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| Intravenous |
| MANAGEMENT OF HYPERTENSION |
| Child:
As methyldopate hydrochloride: 20-40 mg/kg/24 hr or 0.6-1.2 g/m2/24 hr in equally divided doses every 6 hr. Max 65 mg/kg, 2 g/m2 or 3 g daily, whichever is least. |
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| Administration |
May be taken with or without food. |
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| Precautions |
History of haemolytic anaemia, depression, parkinsonism, renal or hepatic impairment. May impair ability to drive or operate machinery. Monitor blood counts and perform LFTs. Elderly. |
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Potentially Life-threatening
Adverse Drug Reactions |
Peripheral oedema; drug fever, mental depression, anxiety, nightmares, drowsiness, headache; dry mouth; orthostatic hypotension, sinus bradycardia, sodium retention, sexual dysfunction, gynaecomastia, hyperprolactinaemia, thrombocytopenia, positive Coombs' test, transient leukopenia or granulocytopenia, cholestasis or hepatitis and heptocellular injury, increased liver enzymes, jaundice, cirrhosis, dyspnoea, SLE-like syndrome. |
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| Adverse Drug Reactions |
Hepatic necrosis, haemolytic anaemia. |
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| Interactions |
Increased risk of severe hypertension with MAOIs. Increased lituhium toxicity. Reduced hypotensive effects with phenothiazines, TCAs and possibly, amphetamines. Additive hypotensive effects with levodopa; psychosis may also occur. Reduced absorption and effects with oral iron preparations. Reduced doses of general anaesthetics may be required. Effect of ephedrine may be reduced. Hypertension may be exacerbated with ephedra, yohimbe and ginseng. CNS depression may be increased when used with valerian, St John's wort, kava kava and gotu kola. Natural licorice causes sodium and water retention and increases potassium loss. Garlic may increase antihypertensive effect. |
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