* Side effects may include: abdominal pain, agitation, anxiety, constipation, decreased sex drive, diarrhea or loose stools, difficulty with ejaculation, dizziness, dry mouth, fatigue, gas, headache, and decreased appetite. They also may include increased sweating, indigestion, insomnia, nausea, nervousness, rash, pain, sleepiness, sore throat, tingling or pins and needles, tremor, vision problems, acne, allergic reaction, altered taste, back pain, blindness, breast development in males, breast pain or enlargement, breathing difficulties, bruise-like marks on the skin, cataracts, changeable emotions, chest pain, cold, clammy skin, conjunctivitis (pinkeye), coughing, difficulty breathing, difficulty swallowing, double vision, dry eyes, eye pain, fainting, feeling faint upon arising from a sitting or lying position, feeling of illness, female and male sexual problems, fluid retention, blushing, frequent urination, hair loss, heart attack, hemorrhoids, hiccups, high blood pressure, high pressure within the eye (glaucoma), hearing problems, hot flushes, impotence, inability to stay seated, increased appetite, increased salivation, increased sex drive, inflamed nasal passages, inflammation of the penis, intolerance to light, irregular heartbeat, itching, joint pains, kidney failure, lack of coordination, lack of sensation, leg cramps, menstrual problems, low blood pressure, migraine, movement problems, muscle cramps or weakness, need to urinate during the night, nosebleed, pain upon urination, prolonged erection, purplish spots on the skin, racing heartbeat, rectal hemorrhage, respiratory infection/lung problems, ringing in the ears, rolling eyes, sensitivity to light, sinus inflammation, skin eruptions or inflammation, sleepwalking, sore on tongue, speech problems, stomach and intestinal inflammation, swelling of the face and throat, swollen wrist and ankles, thirst, throbbing heartbeat, twitching, vaginal inflammation, hemorrhage or discharge, and yawning.