No documented drug–drug interactions for this medicine.
Taking progesterone with food (evening meal) increases bioavailability and reduces acute dizziness/drowsiness.
Take with a meal, always at the same time (site monograph).
Site monograph (progesterone — take at bedtime, with food).
Progesterone is hepatically metabolised and is contraindicated in severe liver disease (applies to most progestogens).
Assess liver function before starting hormonal therapy.
Prontuário Terapêutico INFARMED, 8.3 (progestogens — class hepatic contraindication).
Natural progesterone is used in obstetrics (secondary amenorrhoea, bleeding from luteal insufficiency, threatened miscarriage and preterm birth prevention with short cervix). Annex 1 records "the manufacturer recommends using only if the potential benefit outweighs the possible risk" (factor B/C); studies of vaginal/IM progesterone for preterm birth prevention are favourable. First-generation synthetic progestogens at high doses have a virilisation signal in female fetuses — natural progesterone does not.
Compatible when indicated (luteal insufficiency, preterm birth prevention); use natural progesterone, not high-dose synthetic progestogens.
Avoid; small amounts present in milk (Prontuário, Annex 2, l. 43100-01) — natural progesterone at physiological doses is compatible with breastfeeding; progestogens do not suppress milk production (unlike oestrogens).
Prontuário Terapêutico INFARMED — Annex 1: Progestogens/Progesterone (l. 41372-74, factors B/C); Annex 2 (l. 43100-01). EMC-UK (MHRA) — Progesterone SmPC (Utrogestan).
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Secretory endometrial transformation, ↓ uterine contractility, endometrial protection (with oestrogen).
Progesterone receptor agonist (PR-A and PR-B); transcription regulator of endometrial stabilisation and pregnancy maintenance genes.
Oral micronised: variable absorption with food; vaginal: direct uterine absorption with minimal systemic exposure.
Hepatic reduction to pregnanolone (sedative neurosteroid metabolite); sulphation and glucuronidation; renal excretion.
~ 5–20 min (very short; sustained by metabolites).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
