Are your medicines disrupting your sex life?

Geri_Berri · **Geri_Berri**

Written by Helen Davis, NetDoctor pharmacist

Many medicines are suspected to interfere with sexual function, and about 25 per cent of cases of erectile dysfunction (impotence) seen in clinics result from the side effects of medicines.

However, it is relatively difficult to determine whether a particular medicine can cause impotence or disrupt sexual function in other ways, for one of two reasons. Firstly, many diseases themselves often affect sexual function, so it can be difficult to establish if the dysfunction is a result of the disease or the medicine used to treat it. Secondly, side effects that involve sexual issues are frequently not reported to doctors because of embarrassment. So, the actual rate of sexual dysfunction caused by medicines might be higher than reported.

How can medicines affect sexual function?

The mechanism of sexual function is not fully understood. It involves a complex co-ordination of hormones, chemical messengers in the brain (neurotransmitters such as dopamine and serotonin) and the actual sexual organs themselves. However, in general, the neurotransmitter dopamine increases sexual function, whereas the neurotransmitter serotonin inhibits sexual function. The hormone testosterone is important, as are the blood vessels involved in producing an erection. A medicine may therefore affect sexual function in several ways.

Libido or sex drive

Sex drive is influenced by reproductive hormones, particularly testosterone, which is required for sexual arousal. Medicines that reduce testosterone levels are likely to reduce sex drive. Libido is also affected by your general emotional and physical health. Therefore, medicines that affect any of these aspects, even indirectly by causing drowsiness, lethargy, weight gain or confusion, have the potential to reduce your sex drive.

Arousal and erection

An erection occurs as a result of a co-ordination between nerves, hormones, blood vessels and psychological factors. There are therefore many areas where this can go wrong! Impotence (inability to get or sustain an erection) is not just caused by medicines that have a physical effect on the blood vessels in the penis but also those that act on the brain, or interfere with hormone levels (particularly testosterone), or affect the transmission of nerve messages.

Ejaculation

This occurs after stimulation of alpha receptors in the prostate gland and seminal vesicles. Medicines that block alpha receptors can therefore prevent or delay ejaculation. Various chemicals in the brain are also involved in orgasm and ejaculation, and medicines that affect these chemicals can also cause ejaculatory disturbances.

Medicines that may affect sexual function

Antidepressants, particularly SSRIs (selective serotonin reuptake inhibitors) such as fluoxetine, are the medicines most frequently implicated in causing sexual dysfunction. This is because they work by altering levels of chemicals in the brain. In particular, SSRIs increase serotonin levels, which inhibits sexual function.

Blood pressure lowering (antihypertensive) medicines are the other key culprit, most probably causing sexual problems by their effect on the smooth muscle and blood vessels in the penis.

The following table lists medicines that have had sexual side effects reported in some people during their use. It is important to remember that not everyone experiences side effects with medicines. If you are at all worried that your medicine may be affecting your sexual function, it is important to discuss this with your doctor.

Source - http://www.netdoctor.co.uk/menshealth/feature/medicinessex.htm