Sildenafil Dihydrocodeine

Two men using sildenafil had prolonged erections following orgasm while also taking dihydrocodeine. 

Two men, successfully treated with 100-mg doses of sildenafil for erectile dysfunction, experienced prolonged erections after orgasm while also taking dihydrocodeine 30 to 60 mg every 6 hours for soft tissue injuries. One of them had two erections lasting 4 and 5 hours, and this did not occur on subsequent occasions when the dihydrocodeine was stopped. The other had 2 to 3 hour erections on three occasions during the first week of dihydrocodeine use, but no problems over the next 2 weeks while continuing to take the dihydrocodeine. The reasons are not understood. 

According to the manufacturers of sildenafil, priapism (painful prolonged abnormal erection) associated with its use is rare, and there appear to be no other reports about an interaction between sildenafil and dihydrocodeine. Excessively prolonged erections can have serious consequences and may need urgent treatment. Therefore, the authors suggest it would now be prudent to warn patients about this possible (though remote) problem if opioids are being used, and advise them to contact the prescrib-er if priapism occurs. ... 

GoldmeierD, LambaH. Prolonged erections produced by dihydrocodeine and sildenafil. BMJ... 

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