Antihypeensive of choice in a pregnant lady is: September 2011
Ans. A: Methyldopa Methyldopa is usually safe and preferred as an antihypeensive agent in pregnancy Methyldopa/ L-alpha-Methyl-3, 4-DihydrOxyPhenylAlanine It is an alpha-adrenergic agonist (selective for alpha-2-adrenergic receptors) psychoactive drug used as a sympatholytic or antihypeensive. It continues to have a role in otherwise difficult to treat hypeension and gestational hypeension (also known as pregnancy-induced hypeension (PIH)). Methyldopa is used in the clinical treatment of the following disorders: - Hypeension - Gestational hypeension (or pregnancy-induced hypeension) and pre-eclampsia Methyldopa has a dual mechanism of action: - It is a competitive inhibitor of the enzyme DOPA decarboxylase, also known as aromatic L-amino acid decarboxylase, which conves L-DOPA into dopamine. - Dopamine is a precursor for norepinephrine (noradrenaline) and subsequently epinephrine (adrenaline). - This inhibition results in reduced dopaminergic and adrenergic neurotransmission in the peripheral nervous system. - This effect may lower blood pressure and cause central nervous system effects such as depression, anxiety, apathy, anhedonia, and parkinsonism. - It is conveed to alpha-methylnorepinephrine by dopamine beta-hydroxylase (DBH). - Alpha-methylnorepinephrine is an agonist of presynaptic central nervous system alpha-2-adrenergic receptors. - Activation of these receptors in the brainstem appears to inhibit sympathetic nervous system output and lower blood pressure. This is also the mechanism of action of clonidine. Methyldopa exhibits variable absorption from the gastrointestinal tract. It is metabolized in the liver and intestines and is excreted in urine. Side effects may include: - Psychological Depression and/or even suicidal ideation, as well as nightmares Decreased aleness, awareness, and wakefulness Cognitive and memory impairment Derealization and/or depersonalization, as well as mild psychosis Physiological Miosis Xerostomia Gastrointestinal disturbances such as diarrhea and/or constipation Myalgia or muscle aches, ahralgia or joint pain, and/or paresthesia ("pins and needles") Restless legs syndrome (RLS) Parkinsonian symptoms such as muscle tremors, rigidity, hypokinesia, and/or balance or postural instability Akathisia, ataxia, dyskinesia as well as even tardive dyskinesia, and/or dystonia Bell's palsy or facial paralysis Sexual dysfunction consisting of impaired erectile dysfunction and/or anorgasmia Hyperprolactinemia or excess prolactin, gynecomastia/breast enlargement in males, and/or amenorrhoea or absence of menstrual cycles in females Bradycardia Ohostatic hypotension (also known as postural hypotension) Hepatitis, hepatotoxicity Pancreatitis Haemolytic anaemia Myelotoxicity or bone marrow suppression Lichenoid reactions such as skin lesions and/or rashes
Methyldopa
Frusemide
Nitroprusside
ACE inhibitors