742-20-1

Antihypertensive;Sodium Chloride Symporter Inhibitor

Cyclopenthiazide is a thiazide diuretic. Cyclopenthiazide is used in the treatment of oedema caused by conditions such as kidney disease, liver cirrhosis and pre-menstrual syndrome as well as in the treatment of hypertension.

ChEBI: 6-chloro-3-(cyclopentylmethyl)-1,1-dioxo-3,4-dihydro-2H-1$l^{6},2,4-benzothiadiazine-7-sulfonamide is a benzothiadiazine.

Cyclopenthiazide, a thiazide diuretic, was introduced in 1968. It continues to be used mainly in combination drugs.

Thiazide diuretic:
Hypertension

Heart failure

Oedema

Potentially hazardous interactions with other drugs
Analgesics: increased risk of nephrotoxicity with NSAIDs; antagonism of diuretic effect. Anti-arrhythmics: hypokalaemia leads to increased cardiac toxicity; effects of lidocaine and mexiletine antagonised.
Antibacterials: avoid administration with lymecycline.
Antidepressants: increased risk of hypokalaemia with reboxetine; enhanced hypotensive effect with MAOIs; increased risk of postural hypotension with tricyclics.
Antiepileptics: increased risk of hyponatraemia with carbamazepine.
Antifungals: increased risk of hypokalaemia with amphotericin.
Antihypertensives: enhanced hypotensive effect; increased risk of first dose hypotension with postsynaptic alpha-blockers like prazosin; hypokalaemia increases risk of ventricular arrhythmias with sotalol.
Antipsychotics: hypokalaemia increases risk of ventricular arrhythmias with amisulpride; enhanced hypotensive effect with phenothiazines; hypokalaemia increases risk of ventricular arrhythmias with pimozide - avoid.
Atomoxetine: hypokalaemia increases risk of ventricular arrhythmias.
Cardiac glycosides: increased toxicity if hypokalaemia occurs.
Ciclosporin: increased risk of nephrotoxicity and possibly hypomagnesaemia.
Cytotoxics: increased risk of ventricular arrhythmias due to hypokalaemia with arsenic trioxide; increased risk of nephrotoxicity and ototoxicity with platinum compounds.
Lithium: excretion reduced, increased toxicity

Cyclopenthiazide appears to be entirely excreted unchanged in the urine.