Australian Centre for Sexual Health, St. Luke's Hospital Complex, Sydney, Australia
Correspondence to: CG McMahon, Australian Centre for Sexual Health, St. Luke's Hospital Complex, Hemsley House, 20 Roslyn Street, Potts Point, NSW, Australia 2011. E-mail: email@example.com
The objectives of this study were to evaluate the efficacy and tolerability of high dose sildenafil as a salvage therapy for patients refractory to the maximum recommended dose of sildenafil. Fifty four fully evaluated patients with chronic erectile failure (ED) who had previously failed to respond to a home trial of sildenafil (100 mg) with erections suitable for sexual intercourse were studied. Each man was treated at home with sildenafil at escalating doses of up to 200 mg until either maximal response or intolerable adverse effects occurred. Erectile function was quantified using the erectile function domain of the International Index of Erectile Function (IIEF) before treatment, with sildenafil 100 mg and with maximal dose of sildenafil and a global efficacy question after 4 weeks of treatment.
The mean age of the study group was 59.6±11.2 y. 13/54 (24%) had arteriogenic ED, 16/54 (30%) had mixed vasculogenic ED, 9/54 (17%) had cavernosal veno-occlusive dysfunction, 11/54 (20%) had post radical retropubic prostatectomy ED and 5/54 (9%) had psychogenic ED. 13/54 (24.1%) responded to sildenafil at a median maximal dose of 200 mg, 4/13 required 150 mg and 9/13 required 200 mg. 41/54 (76%) failed to respond to sildenafil. Mean IIEF question 3 and 4 scores were 1.5 and 1.4 at baseline, 2.2 and 1.9 with sildenafil 100 mg, 2.8 and 2.5 with sildenafil 150 mg and 3.0 and 2.9 with sildenafil 200 mg, respectively. After 4 weeks, treatment was regarded as having improved their erections by 37%, 46.3% and 68% of patients with sildenafil 100 mg, 150 mg and 200 mg, respectively. 34/54 (63%) reported adverse effects with maximal dose sildenafil comprising headache (19), facial flushing (32), dyspepsia (14), nasal congestion (11), dizziness (5) and visual disturbances (5). 4/13 (31%) responders refused to continue treatment due to adverse effects.
In conclusion, sildenafil at doses of up to 200 mg is an effective salvage therapy for 24.1% of previous sildenafil non-responders but is limited by a significantly higher incidence of adverse effects and a 31% treatment discontinuation rate.
Viagra™ DRUG INFO
IMPORTANT NOTE: The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you.
SILDENAFIL - ORAL (sill-DEN-uh-fil)
COMMON BRAND NAME(S): Viagra™
USES OF VIAGRA: This medication is used to treat male sexual function problems (erection problems).
HOW TO USE VIAGRA: This drug is taken by mouth as needed between four hours and one-half hour before sexual activity (about one hour before is most effective). Take only as directed, usually once daily as needed. Sildenafil works along with sexual stimulation to help achieve an erection.
SIDE EFFECTS OF VIAGRA: Headache, flushing, stomach upset, nasal stuffiness, diarrhea and dizziness might occur. If these effects persist or worsen, notify your doctor promptly. Unlikely but report promptly: painful or other urination problems, vision problems, skin rash. Very unlikely but report promptly: chest pain, fainting, foot or ankle swelling. If you experience a painful or prolonged erection (lasting longer than 4 hours), stop using this drug and seek immediate medical attention. If you notice other effects not listed above, contact your doctor or pharmacist.
PRECAUTIONS WHEN USING VIAGRA: Before using this drug, tell your doctor your medical history, including: allergies (especially drug allergies), penis conditions such as fibrosis/scarring (e.g., Peyronie's disease), history of painful/prolonged erection (priapism), sickle cell anemia, blood system cancers (such as leukemia or myeloma), eye problems (retina diseases), kidney or liver disease, bleeding disorders, active stomach ulcers, heart disease, stroke, very high or low blood pressure. Limit alcohol intake, as it may aggravate side effects of this drug. Since this drug may cause dizziness, caution is advised when performing tasks requiring alertness (e.g., driving). To avoid dizziness and lightheadedness when rising from a seated or lying position, get up slowly. This drug is not to be used in women or children. The elderly may be more sensitive to the side effects of this drug, therefore caution is advised in this group.
DRUG INTERACTIONS OF VIAGRA: Tell your doctor of all nonprescription and prescription medication you may use, especially of: nitrate medications (e.g., nitroglycerin, isosorbide dinitrate), nitroprusside (any "nitric oxide donor" medicines), cimetidine, erythromycin, azole antifungals (e.g., itraconazole, ketoconazole), mibefradil, rifamycins (e.g., rifampin), high blood pressure medicines, certain HIV protease inhibitors (such as saquinavir, ritonavir, amprenavir), delavirdine. Do not start or stop any medicine without doctor or pharmacist approval.
OVERDOSE OF VIAGRA: If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include severe dizziness, fainting, or prolonged erection.
NOTES On VIAGRA: Do not share this medication with others, since they may have a problem that is not effectively treated by this drug. Use of this drug does not protect against sexually transmitted diseases (e.g., HIV, Hepatitis B, gonorrhea, syphilis)
MISSED DOSE OF VIAGRA: Not applicable.
STORAGE OF VIAGRA: Store at room temperature between 59 and 86 degrees F (15-30 degrees C) away from light and moisture.