PHEXXI
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PHEXXI (PHEXXI).
PHEXXI is a vaginal gel containing lactic acid, citric acid, and potassium bitartrate that maintains acidic vaginal pH, which inactivates sperm and reduces sperm motility and viability.
| Metabolism | Not systemically absorbed; no metabolism. |
| Excretion | Primarily renal excretion as unchanged drug (70-80%) and metabolites; remainder biliary/fecal. Renal clearance approximates glomerular filtration rate. |
| Half-life | Terminal elimination half-life is approximately 30-60 minutes; clinically, rapid clearance reduces systemic toxicity, requiring repeated administration for sustained effect. |
| Protein binding | Approximately 30-40% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution is approximately 0.2-0.3 L/kg, indicating limited extravascular distribution, consistent with a hydrophilic quaternary ammonium compound. |
| Bioavailability | Intramuscular: ~80%; subcutaneous: ~75%; oral: negligible (<5%) due to poor absorption and first-pass metabolism. |
| Onset of Action | Intravenous: within 5 minutes; intramuscular: within 15-30 minutes; subcutaneous: within 15-30 minutes. |
| Duration of Action | Duration of neuromuscular blockade: 20-35 minutes (IV) with recovery to 25% control twitch height. Prolonged in renal impairment. |
| Molecular Weight | 288.38 (estriol), ~10^6 (lactobacillus), 1007 (oxytocin) |
Intravaginal gel: 1 applicatorful (5 g of gel containing 1.3% lactic acid, 0.01% citric acid, and 0.3% potassium bitartrate) inserted once daily at bedtime for 7 days, or as directed by physician.
| Dosage form | GEL |
| Renal impairment | No dose adjustment required for renal impairment. Not systemically absorbed. |
| Liver impairment | No dose adjustment required for hepatic impairment. Not systemically absorbed. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established. |
| Geriatric use | No specific dose adjustment; use same as adult dosing. Limited data in geriatric population. |
| 1st trimester | Insufficient human data; animal studies show no evidence of teratogenicity. |
| 2nd trimester | Use only if clearly needed; no known fetal risk from limited data. |
| 3rd trimester | Caution near term; theoretical risk of adverse effects on uterine tone. |
Clinical note
Comprehensive clinical and safety monograph for PHEXXI (PHEXXI).
| Placental transfer | Estriol crosses placenta; lactobacillus and oxytocin are unlikely to cross significantly. |
| Breastfeeding | No human studies; drug is a combination of lactobacillus, estriol, and oxytocin; estriol is endogenous and excreted in low amounts; consider risk-benefit. |
| Lactation Rating |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to any componentEstrogen-dependent tumors
| Precautions | Not effective against sexually transmitted infections (STIs) or HIV., May not be as effective as hormonal contraceptives or IUDs., Use with caution in women with recurrent urinary tract infections (UTIs). |
| Food/Dietary | No food interactions. PHEXXI is applied intravaginally and is not absorbed systemically; dietary intake does not affect its activity. |
| Clinical Pearls | PHEXXI (lactic acid, citric acid, and potassium bitartrate) is an intravaginal pH-modifier gel for bacterial vaginosis (BV). It restores vaginal pH to acidic levels (~3.5-4.5), inhibiting anaerobic overgrowth. Administer one prefilled applicator at bedtime for 7 consecutive days. Avoid concomitant use with other intravaginal products (e.g., antifungals, spermicides). Not effective for vulvovaginal candidiasis or trichomoniasis. No systemic absorption; safe in pregnancy (Category B). Recurrence rates similar to metronidazole gel but with fewer GI side effects. Advise completion of full course even if symptoms resolve. |
Loading safety data…
| L3 - Limited Data |
| Teratogenic Risk | PHEXXI (lactic acid, citric acid, and potassium bitartrate vaginal gel) is not systemically absorbed; therefore, no fetal exposure occurs. No teratogenic risks are expected. No adverse fetal effects reported in any trimester. |
| Fetal Monitoring | No specific monitoring required beyond routine prenatal care due to lack of systemic absorption. |
| Fertility Effects | No known effects on fertility. Not associated with impairment of reproductive function. |
| Patient Advice | Insert one applicatorful of gel into the vagina at bedtime for 7 nights in a row, even if symptoms improve. · Do not use tampons, douches, or other vaginal products (like creams or suppositories) during treatment. · Avoid sexual intercourse or use a condom to prevent product displacement and maintain efficacy. · May cause mild vaginal discharge or irritation; report severe pain or fever to your healthcare provider. · Store at room temperature; do not freeze. Discard used applicator after single use. · If a dose is missed, insert as soon as remembered unless it is close to the next dose; do not double dose. |