Guanethidine

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Guanethidine
Systematic (IUPAC) name
2-(2-azocan-1-ylethyl)guanidine
Identifiers
CAS number	645-43-2
ATC code	C02CC02 S01EX01
PubChem	3518
DrugBank	APRD01007
Chemical data
Formula	C10H22N4
Mol. mass	198.309 g/mol
Pharmacokinetic data
Bioavailability	?
Metabolism	?
Half life	1.5 days
Excretion	?
Therapeutic considerations
Pregnancy cat.	?
Legal status
Routes	?

Guanethidine is an antihypertensive drug that reduces the release of catecholamines, such as noradrenaline. Its mechanism is inhibition of the Mg++ATPase dependent pump. Side effects include orthostatic and exercise hypotension, sexual dysfunction, and diarrhea.

It is no longer available in the US due to side effects and because substantially better drugs are available. It is still licensed in some countries, e.g. UK, for the rapid control of blood pressure in a hypertensive emergency.

Guanethidine is transported by uptake 1 into the presynaptic terminal. (In this it competes with noradrenaline so can potentiate exogenously applied noradrenaline). Once inside the terminal it blocks the release of noradrenaline in response to arrival of an action potential. Spontaneous release is not affected.

Intravenous nerve block (Bier block) using guanethidine can be used to treat chronic pain caused by complex regional pain syndrome.

v • d • e Antihypertensives (C02) and diuretics (C03) Sympatholytic agents (including alpha) centrally acting/antiadrenergics: Clonidine • Guanfacine • Methyldopa • Moxonidine • Rilmenidine • adrenergic uptake inhibitor (Rescinnamine, Reserpine) ganglion-blocking/nicotinic antagonist (Mecamylamine, Trimethaphan) peripherally acting/antiadrenergics (Prazosin, Guanethidine, Indoramin, Doxazosin) Vasodilators Diazoxide • Hydralazine • Minoxidil • Nitroprusside • Phentolamine Other antihypertensives serotonin antagonist (Ketanserin) • endothelin receptor antagonist (Bosentan, Ambrisentan, Sitaxsentan) Low ceiling diuretics Thiazide (Bendroflumethiazide, Chlorothiazide, Hydrochlorothiazide) • Chlortalidone • Indapamide • Quinethazone • Mersalyl • Metolazone • Theobromine • Cicletanine High ceiling diuretics Loop diuretic (Bumetanide, Furosemide, Torasemide) Potassium-sparing diuretics ESC blockers (Amiloride, Triamterene) • aldosterone antagonists (Spironolactone, Eplerenone, Potassium canrenoate, Canrenone)

v • d • e Ophthalmologicals: antiglaucoma preparations and miotics (S01E) Sympathomimetics Apraclonidine • Brimonidine • Clonidine • Dipivefrine • Epinephrine Parasympathomimetics Aceclidine • Acetylcholine • Carbachol • Demecarium • Echothiophate • Stigmine (Fluostigmine, Neostigmine, Physostigmine) • Paraoxon • Pilocarpine Carbonic anhydrase inhibitors Acetazolamide • Brinzolamide • Diclofenamide • Dorzolamide • Methazolamide Beta blocking agents Befunolol • Betaxolol • Carteolol • Levobunolol • Metipranolol • Timolol Prostaglandin analogues Bimatoprost • Latanoprost • Travoprost • Unoprostone Other agents Dapiprazole • Guanethidine