Spotting or periods on the pill do not mean that the pill has not worked.
In the treatment of PAH, sildenafil is available in tablets 20 mg, oral suspension 10 mg mL, and injectable 10 mg 125 mL forms.
Caution is also recommended in prescribing the drug to individuals with retinitis pigmentosa, a rare genetic eye disorder.
For best results, try to take your dosage of sildenafil around one hour before you plan to have sex.