From the Guidelines
If you suspect an overdose of finasteride or minoxidil, seek immediate medical attention. For finasteride overdose, there is no specific antidote, but supportive care is provided based on symptoms. Even large doses of finasteride (up to 400 mg) have not shown serious adverse effects in clinical studies 1. For minoxidil overdose, symptoms may include rapid heart rate, low blood pressure, fluid retention, and dizziness due to its vasodilating properties. Treatment typically involves monitoring vital signs, administering activated charcoal if the ingestion was recent, and providing supportive care to manage cardiovascular effects. Minoxidil overdose is potentially more dangerous than finasteride due to its systemic effects on blood pressure, as indicated by its use in hypertension management with dosages ranging from 5–100 mg/day 1. The severity of an overdose depends on the amount ingested, time since ingestion, and individual factors like age and health status. Prevention is best - store medications safely, follow prescribed dosages, and keep them out of reach of children and pets. Some key points to consider in managing overdose include:
- Monitoring for signs of cardiovascular instability
- Administering activated charcoal for recent ingestion
- Providing supportive care for symptoms
- Being aware of the potential for more severe effects with minoxidil due to its vasodilating properties. Given the potential risks, it is crucial to prioritize prevention and seek medical help immediately if an overdose is suspected.
From the FDA Drug Label
Patients have received single doses of finasteride tablets up to 400 mg and multiple doses of finasteride tablets up to 80 mg/day for three months without adverse effects. Until further experience is obtained, no specific treatment for an overdose with finasteride tablets can be recommended. Significant lethality was observed in male and female mice at single oral doses of 1,500 mg/m 2 (500 mg/kg) and in female and male rats at single oral doses of 2,360 mg/m 2 (400 mg/kg) and 5,900 mg/m 2 (1,000 mg/kg), respectively.
- Finasteride overdose: There is no specific treatment recommended for an overdose with finasteride tablets 2.
- Minoxidil overdose: The FDA drug label does not answer the question about minoxidil overdose.
- Key points:
- No adverse effects were observed in patients receiving single doses of finasteride up to 400 mg.
- Significant lethality was observed in animal studies at high doses.
- No specific treatment is recommended for finasteride overdose.
From the Research
Finasteride and Minoxidil Overdose
- There is limited information available on the specific effects of finasteride and minoxidil overdose in the provided studies.
- However, the studies suggest that both finasteride and minoxidil can cause side effects, even at recommended doses 3, 4, 5, 6, 7.
- Finasteride has been associated with sexual dysfunction, neuropsychiatric side effects, and gynecomastia 4, 6.
- Minoxidil has been linked to hypertrichosis, cardiovascular symptoms, and local side effects such as itching, shedding, and dandruff 3, 5.
- The combination of topical finasteride and minoxidil has been shown to have similar safety and effectiveness as topical minoxidil alone for treating male androgenetic alopecia 5.
- A systematic review of in vitro and in vivo evidence suggests that finasteride and minoxidil can act as hormone disruptors, causing oxidative stress and morphological changes in the testis and epididymis 7.
Side Effects and Interactions
- Finasteride and minoxidil can cause a range of side effects, including sexual dysfunction, neuropsychiatric side effects, and local skin reactions 3, 4, 5, 6, 7.
- The studies suggest that finasteride may be more harmful to male reproductive health, with associations with reproductive injuries, erectile dysfunction, decreased libido, and reduced semen volume 7.
- Minoxidil, on the other hand, has been shown to act through multiple pathways to promote hair growth, including as a vasodilator, anti-inflammatory agent, and Wnt/β-catenin signaling inducer 3.