quinapril: No evidence of CYP-dependent metabolism. Hydrochlorthiazide: Not metabolised. Probably no CYP-affinity. Clinical experience of non-porphyrinogenicity. Conflicting evidence.

quinapril: HCl-salt of quinapril, which is a prodrug of the metabolite quinaprilate is excreted unchanged by the kidneys. Hydrochlorthiazide: thiazide diuretic, sulfonamide congener. Eliminated in urine in unchanged form. Probably no CYP-affinity. Hydrochlorthiazide: South African list: use. French list: authorized. Australian list: unsafe associated with attacks. Thunell, patient report (n=1): tolerated. Andersson, patient reports (n=10): tolerated. Martindale: Hydrochlorthiazide has been associated with acute attacks of porphyria and is considred unsafe in porphyric patients. EPI-list: sulfonamides are on the unsafe list.

Uneventful use reported in 1 patient with acute porphyria.