Lamotrigine (Lamictal) and Gynecomastia
Lamotrigine is not significantly associated with gynecomastia, unlike other medications such as spironolactone which has a well-documented risk of this side effect. 1
Medications Known to Cause Gynecomastia
Gynecomastia is a benign condition characterized by breast tissue enlargement in males. Several medications have been definitively linked to this condition:
- Spironolactone - This aldosterone antagonist is strongly associated with gynecomastia, with a significantly higher risk compared to eplerenone (another medication in the same class) 1
- Other medications with good evidence of association: 2
- Cimetidine
- Ketoconazole
- Human growth hormone (hGH)
- Estrogens
- Human chorionic gonadotropin (hCG)
- Anti-androgens
- GnRH analogs
- 5-α reductase inhibitors
Medications with Probable Association to Gynecomastia
- Risperidone
- Calcium channel blockers (verapamil, nifedipine)
- Omeprazole
- Alkylating agents
- HIV medications (particularly efavirenz)
- Anabolic steroids
- Alcohol
- Opioids 2
Pathophysiology of Drug-Induced Gynecomastia
Gynecomastia typically develops due to:
- An imbalance in the estrogen/androgen ratio
- Increased prolactin levels 3
- Interference with hormone production or action 2
Lamotrigine and Gynecomastia
Lamotrigine (Lamictal) is not listed among medications with established or probable association with gynecomastia in any of the comprehensive reviews on drug-induced gynecomastia 3, 2, 4. Unlike medications such as spironolactone, which has a documented 9.1% rate of gynecomastia compared to 1.3% in placebo groups, lamotrigine does not appear in the literature as a significant cause 1.
Clinical Implications
When evaluating a patient with gynecomastia who is taking lamotrigine:
- Consider other medications in the patient's regimen that have stronger associations with gynecomastia 2
- Look for combinations of medications that might have synergistic effects, as seen in cases with certain antidepressants 5
- Evaluate for other common causes of gynecomastia (hormonal disorders, liver disease, obesity, etc.) 3
Common Pitfalls in Evaluating Drug-Induced Gynecomastia
- Failure to consider medication combinations: Some cases of gynecomastia occur only when certain medications are used together 5
- Overlooking dose-dependent effects: Some medications cause gynecomastia in a dose-dependent manner 6
- Attributing gynecomastia to the wrong medication: When multiple medications are being taken, it's important to identify which one is most likely responsible 2
Conclusion
Based on current evidence, lamotrigine (Lamictal) is not significantly associated with gynecomastia. If a patient taking lamotrigine develops gynecomastia, other medications or medical conditions should be considered as more likely causes.