Griseofulvin

Nausea, vomiting, flushing, tachycardia, and severe hypotension have been reported following alcohol ingestion during griseofulvin therapy.

Phototoxic agent that may cause severe phototoxic skin reaction (severe sunburn). Avoid for 24 hours before and after ALA administration.

Increases metabolism of contraceptive steroids, reducing contraceptive effectiveness and potentially resulting in unintended pregnancy or unscheduled bleeding.

May reduce contraceptive effectiveness and result in unintended pregnancy or breakthrough bleeding by increasing metabolism of contraceptive steroids.

May decrease contraceptive effectiveness and increase breakthrough bleeding through CYP3A4 induction.

May decrease plasma concentrations of COCs and potentially diminish effectiveness or increase breakthrough bleeding.

Barbiturates usually depress griseofulvin activity by decreasing plasma levels, requiring dosage adjustment of griseofulvin.

Griseofulvin may reduce cyclosporine levels, resulting in decreased pharmacologic effects.

Possible association with reduced efficacy and breakthrough bleeding, though less marked than with rifampin.

May decrease systemic concentrations of hormonal contraceptives and diminish effectiveness or increase breakthrough bleeding.

Induces CYP3A4 enzyme, may decrease effectiveness of COCs or increase breakthrough bleeding.

May decrease the effectiveness of hormonal contraceptives or increase breakthrough bleeding through CYP3A4 enzyme induction.

Enzyme inducer that may decrease effectiveness of COCs or increase breakthrough bleeding. Use back-up contraception.

CYP3A4 enzyme inducer that may decrease the effectiveness of the contraceptive or increase breakthrough bleeding.

Griseofulvin may enhance hepatic metabolism of estrogens, reducing effectiveness and causing menstrual irregularities. Alternate birth control may be indicated.

Possible association with reduced contraceptive efficacy, though less marked than rifampin.

May decrease plasma concentrations of etonogestrel and diminish contraceptive effectiveness or increase breakthrough bleeding.

CYP3A4 enzyme inducer that may decrease plasma concentrations of etonogestrel and ethinyl estradiol, potentially diminishing contraceptive effectiveness or increasing breakthrough bleeding.

Induces CYP3A4, may decrease plasma concentrations of CHCs and potentially diminish effectiveness or increase breakthrough bleeding.

Griseofulvin induces CYP3A4 and may decrease plasma concentrations of COCs, potentially diminishing contraceptive effectiveness or increasing breakthrough bleeding.

Griseofulvin induces CYP3A4 enzymes, potentially decreasing contraceptive effectiveness and increasing breakthrough bleeding.

May decrease effectiveness of medroxyprogesterone acetate through enzyme induction. Counsel use of back-up or alternative contraception.

Enzyme inducer that may decrease plasma concentrations of CHCs and potentially diminish effectiveness or increase breakthrough bleeding.

CYP3A4 inducer that may decrease the effectiveness of COCs or increase breakthrough bleeding.

Enzyme inducer that may decrease plasma concentrations of norethindrone and ethinyl estradiol, potentially diminishing contraceptive effectiveness or increasing breakthrough bleeding.

May decrease plasma concentrations and efficacy of contraceptive; may increase breakthrough bleeding.

Griseofulvin may enhance metabolism of the estrogen component, reducing contraceptive effectiveness and causing menstrual irregularities.

Barbiturates interfere with absorption of orally administered griseofulvin, decreasing blood levels. Concomitant administration should preferably be avoided.

Phenobarbital interferes with absorption of orally administered griseofulvin, decreasing blood levels. Concomitant administration should preferably be avoided.

Phenobarbital appears to interfere with absorption of orally administered griseofulvin, decreasing its blood level. Concomitant administration should preferably be avoided.

Concomitant use may increase the risk of photosensitivity reaction. Avoid concomitant use with other photosensitizing agents.

Serum salicylate concentrations may be decreased when griseofulvin is given concomitantly.

Metabolic enzyme inducer that may decrease systemic concentrations of estrogen and/or progestin, potentially diminishing contraceptive effectiveness.

CYP3A4 inducer decreases plasma concentrations of ulipristal acetate and may decrease its effectiveness as emergency contraception.

Other photosensitizing agents that could increase the potential for skin photosensitivity reactions.

Griseofulvin decreases the activity of warfarin-type anticoagulants, requiring dosage adjustment of the anticoagulant during and after griseofulvin therapy.