Triamterine

Triamterene

Clinical data
Trade names	Dyrenium, Dyazide, Maxzide
AHFS/Drugs.com	Monograph
MedlinePlus	a682337
Pregnancy category	AU: C US: C (Risk not ruled out)
Routes of administration	oral
ATC code	C03DB02 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Bioavailability	30-70%
Protein binding	67%
Metabolism	conjugated to hydroxytriamterene
Biological half-life	1-2 hours, active metabolite 3 hours
Excretion	renal <50%, 21% unchanged
Identifiers
IUPAC name 6-phenylpteridine-2,4,7-triamine
CAS Number	396-01-0 Y
PubChem CID	5546
IUPHAR/BPS	4329
DrugBank	DB00384 Y
ChemSpider	5345 Y
UNII	WS821Z52LQ
KEGG	D00386 N
ChEMBL	CHEMBL585 Y
ECHA InfoCard	100.006.278
Chemical and physical data
Formula	C12H11N7
Molar mass	253.263 g/mol
InChI InChI=1S/C12H11N7/c13-9-7(6-4-2-1-3-5-6)16-8-10(14)18-12(15)19-11(8)17-9/h1-5H,(H6,13,14,15,17,18,19) Y Key:FNYLWPVRPXGIIP-UHFFFAOYSA-N Y
NY (what is this?)

Triamterene (trade name Dyrenium) is a potassium-sparing diuretic used in combination with thiazide diuretics for the treatment of hypertension and edema. In combination with hydrochlorothiazide, it is marketed under the names Maxzide and Dyazide.

Triamterene directly blocks the epithelial sodium channel (ENaC) on the lumen side of the kidney collecting tubule. Other diuretics cause a decrease in the sodium concentration of the forming urine due to the entry of sodium into the cell via the ENaC, and the concomitant exit of potassium from the principal cell into the forming urine. Blocking ENaC prevents this from happening. Amiloride works in the same way. Sodium channel blockers directly inhibit the entry of sodium into the sodium channels.

Common side effects may include a depletion of sodium, folic acid and calcium, nausea, vomiting, diarrhea, headache, dizziness, fatigue, and dry mouth. Serious side effects may include heart palpitations, tingling/numbness, fever, chills, sore throat, rash, and back pain. Triamterene can also cause kidney stones through direct crystallization or by seeding calcium oxalate stones. Triamterene is best avoided in patients with chronic kidney disease due to the possibility of hyperkalemia. People using this drug should use salt substitute cautiously.

Triamterene may impart a blue fluorescent color to the urine.

Diabetes: Use with caution in patients with prediabetes or diabetes mellitus as there may be a change in glucose control.