How much viagra should I take for recreational use?

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Our two year study funded by the Economic and Social Research Council explored the health of customers in night clubs, looking in particular at illicit drug use. As part of this research, 2056 customers completed short structured interviews in three clubs in north west England over six months in 1998. Fieldwork in two clubs occurred before sildenafil was licensed in the United Kingdom (September 1998). In the third club it occurred during October. Interviews with customers and staff showed that supplies of sildenafil were readily available in the third club for £10 a tablet (50 mg). We therefore incorporated questions on sildenafil usage into the survey (n=519).

Sildenafil was used as a recreational drug by 15 respondents (3%) (10 men, 5 women; 14 white, 1 African-Caribbean; mean age 26, range 19-34). All reported having used at least one other illegal or illicit drug in their lifetimes. Fourteen had used amyl nitrite (poppers), 13 amphetamines, 13 cannabis, 11 methylenedioxymethamphetamine (“ecstasy”), 10 cocaine, 8 (γ-hydroxybutyric acid, 6 lysergide (LSD), 5 tranquillisers, 2 crack cocaine, and 1 heroin. Fourteen had used drugs within the previous three months. Most reported having taken sildenafil simultaneously with illegal drugs (methylenedioxymethamphetamine, cocaine, cannabis), illicit drugs (amyl nitrite, (γ-hydroxybutyric acid), and alcohol.

Some used sildenafil in clubs, others at home. All reported positive effects: enhanced sexual desire and love making and feelings of “warmth.” Fewer than half reported negative effects: headaches, genital soreness, and intoxication. All said they would take the drug again, which had been obtained from friends, dealers, sex shops, and the internet.

These results show potentially dangerous recreational use of sildenafil in combination with other drugs. The combination with amyl nitrate is particularly worrying as both drugs dilate blood vessels, which can result in a dangerous drop in blood pressure and possibly myocardial infarction or stroke.

Within weeks of being licensed sildenafil was available in English night clubs, which shows the willingness of women and men to experiment with drugs. Our findings also provide further evidence for the normalisation of recreational drug use in Britain.

By selecting a treatment on the Numan homepage, consumers will be able to create an account and complete a short questionnaire covering symptoms and medical history. Then a member of Numan’s qualified clinical team will assess their suitability for the treatment. Once approval is granted, a prescription is created and the tablets are shipped and delivered within 48 hours.

Numan next plans to expand its health and grooming offering to include skin and hair treatment for men.

Papafloratos says: “We’re not just providing an online pharmacy though. We’re putting real emphasis on providing you with the knowledge you need to make the right decisions for you. So we’re releasing The Book of Erections — an in-depth guide on how your erections come about, or sometimes don’t and what you can do about it. We’re also supporting that with in-depth information on our blog.”

He says the startup ran a survey of 1,000 men and 1,000 women in the U.K. earlier this year and found that from the men who reported having erectile dysfunction symptoms, only 42 percent sought help on the issue.

Sildenafil

Before taking sildenafil,

  • tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil products. Ask your pharmacist for a list of the ingredients.
  • do not take sildenafil if you are taking or have recently taken riociguat (Adempas) or nitrates (medications for chest pain) such as isosorbide dinitrate (Isordil), isosorbide mononitrate (Monoket), and nitroglycerin (Minitran, Nitro-Dur, Nitromist, Nitrostat, others). Nitrates come as tablets, sublingual (under the tongue) tablets, sprays, patches, pastes, and ointments. Ask your doctor if you are not sure whether any of your medications contain nitrates.
  • do not take street drugs containing nitrates such as amyl nitrate and butyl nitrate (‘poppers’) while taking sildenafil.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: alpha blockers such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), tamsulosin (Flomax, in Jalyn), and terazosin; amlodipine (Norvasc, in Amturnide, in Tekamlo); certain antifungals such as itraconazole (Onmel, Sporanox) and ketoconazole (Nizoral); anticoagulants (‘blood thinners’) such as warfarin (Coumadin, Jantoven); certain barbiturates such as butalbital (in Butapap, in Fioricet, in Fiorinal, others) and secobarbital (Seconal); beta blockers such as atenolol (Tenormin, in Tenoretic), labetalol (Trandate), metoprolol (Lopressor, Toprol XL, in Dutoprol), nadolol (Corgard, in Corzide), and propranolol (Hemangeol, Inderal LA, InnoPran); bosentan (Tracleer); cimetidine ; efavirenz (Sustiva, in Atripla); erythromycin (E.E.S., E-Mycin, Erythrocin); HIV protease inhibitors including amprenavir (Agenerase; no longer available in the U.S.), atazanavir (Reyataz, in Evotaz), darunavir (Prezista, in Prezcobix), fosamprenavir (Lexiva), indinavir (Crixivan), lopinavir (in Kaletra), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), saquinavir (Invirase), and tipranavir (Aptivus); nevirapine (Viramune); other medications or devices to treat erectile dysfunction; medications for high blood pressure; certain medications for seizures including carbamazepine (Carbatrol, Epitol, Tegretol, others), phenobarbital, and phenytoin (Dilantin, Phenytek); rifabutin (Mycobutin); and rifampin (Rifadin, Rimactane, in Rifamate, in Rifater). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with sildenafil, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor what herbal products you are taking or plan to take, especially St. John’s wort.
  • tell your doctor if you smoke, if you have ever had an erection that lasted for several hours, and if you have recently lost a large amount of body fluids (dehydration). This can happen if you are sick with fever, diarrhea, or vomiting; sweat a lot; or do not drink enough liquids. Also tell your doctor if you have or have ever had pulmonary veno-occlusive disease (PVOD; blockage of veins in the lungs); a stomach ulcer; heart, kidney, or liver disease; a heart attack; an irregular heartbeat; a stroke; chest pain; high or low blood pressure; high cholesterol; a bleeding disorder; blood circulation problems;blood cell problems such as sickle cell anemia (a disease of the red blood cells), multiple myeloma (cancer of the plasma cells), or leukemia (cancer of the white blood cells); conditions affecting the shape of the penis (e.g., angulation, cavernosal fibrosis, or Peyronie’s disease); or diabetes. Also tell your doctor if you or any of your family members have or have ever had an eye disease such as retinitis pigmentosa (an inherited eye condition that causes loss of vision) or if you have ever had sudden severe vision loss, especially if you were told that the vision loss was caused by a blockage of blood flow to the nerves that help you see.
  • if you are a woman and you are taking sildenafil to treat PAH, tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking sildenafil, call your doctor.
  • if you are having surgery, including dental surgery, tell your doctor or dentist that you are taking sildenafil.
  • if you are taking sildenafil to treat erectile dysfunction, tell your doctor if you have ever been advised by a healthcare professional to avoid sexual activity for medical reasons or if you have ever experienced chest pain during sexual activity. Sexual activity may be a strain on your heart, especially if you have heart disease. If you experience chest pain, dizziness, or nausea during sexual activity, call your doctor immediately and avoid sexual activity until your doctor tells you otherwise.
  • tell all your healthcare providers that you are taking sildenafil. If you ever need emergency medical treatment for a heart problem, the healthcare providers who treat you will need to know when you last took sildenafil.

VIAGRA BLUNTS EFFECTS OF STRESS ON THE HUMAN HEART

While sildenafil is more widely known for helping genital blood vessels expand to maintain an erection and, more recently, as a treatment for pulmonary hypertension, it has been thought to have little direct effect on the human heart.

In the heart, sildenafil blunts the strengthened heartbeat caused by chemically induced stress, thereby lessening the excess amount of blood and force used to pump it to the body, according to study senior author and cardiologist David Kass, M.D., a professor at The Johns Hopkins University School of Medicine and its Heart Institute.

“Sildenafil effectively puts a ‘brake’ on chemical stimulation of the heart,” says Kass.

The researchers’ findings, which appear in the journal Circulation online Oct. 24, are believed to be the first confirmation in humans that sildenafil has a direct effect on the heart. Previous research by Kass and his team showed that sildenafil had such effects in mice, blocking the short-term effects of hormonal stress in the heart. Related studies by the group also showed that sildenafil prevents and reverses the long-term effects in the heart from chronic high blood pressure.

Moreover, Kass adds, the latest Hopkins results confirm that sildenafil helps control heart function only when the heart is under duress, but has little impact under normal conditions.

Separate research from Kass and his team published earlier this year in the journal Nature Medicine showed that, in mice, sildenafil could reverse the negative effects on heart muscle weakened by heart failure and enlargement, a condition called hypertrophy. “But we had no firm evidence as to whether or how this therapy might work in the human heart. Our latest research provides firm evidence this drug does indeed have an important impact on the heart.”

Thirty-five healthy men and women, with an average age of 30 and no previous signs of coronary artery disease, participated in the six-month study. Within a three-hour timeframe, each participant received two separate injections of dobutamine (5 micrograms per kilogram for five minutes), a synthetic, adrenaline-like chemical that increases heart rate and pumping strength.

Between injections, study participants were randomly assigned to a group that was treated with sildenafil (100 milligrams taken orally) or to a group given a sugar pill placebo. All participants were then given the second dobutamine injection to see what effects sildenafil or placebo had on the heart.

Measurements of heart function were made before and after each injection. This included blood pressure readings, electrocardiograms and echocardiograms, as well as blood samples to confirm relatively equal levels of sildenafil and other enzymes.

Results showed that each dobutamine injection stimulated heart function, increasing heart rate and the force of each heartbeat used to pump blood throughout the body.

“This stimulation is similar to the way the nervous system normally increases heart function when triggered by emotional or exercise stress, or in diseases such as heart failure,” adds Kass.

After the first injection of dobutamine, the force of heart contraction increased by 150 percent in both groups. And in the placebo group, this increase repeated itself after the second injection. However, in the group treated with sildenafil, the increased heartbeat was slowed by 50 percent, resulting in a smaller increase in blood flow and blood pressure generated by the heart in response to chemical stimulation.

Between injections, heart function was not altered in the sildenafil group, demonstrating the absence of adverse side effects on the resting human heart.

“Knowing more about the effects of sildenafil on heart function will allow for safer evaluation of its use as a treatment for heart problems,” says Kass. “Until now, it was widely thought that drugs like sildenafil had no effects on the human heart and that its only purpose was vasodilation in the penis and the lungs.

“Our results set the stage for further studies of sildenafil’s immediate and long-term effects on the heart and its ability to modify other neurohormonal and stress stimuli, including adrenaline and hypertension,” he adds.

While the precise biological actions of sildenafil in the heart are not fully understood, the drug is known to work by stopping the action of an enzyme, called phosphodiesterase 5 (PDE5A), the researcher says. This enzyme is involved in the breakdown of a key molecule, cyclic GMP, which helps control stresses and limit overgrowth in the heart. PDE5A is also the biological pathway blocked in the penis by sildenafil to promote the relaxation of blood vessels and maintain erections.

Funding for this study was provided by the National Institutes of Health (NIH), the Peter Belfer Laboratory Foundation and the Bernard Family Foundation. The makers of the drug had no involvement in the design or support of the research.

– JHM –

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