Science and Research

Gabapentin-Induced Sexual Dysfunction

July 22, 2021

Erectile dysfunction happens to an estimated 50% of guys over the age of 40. While causes can vary, many common medications for other conditions are known to contribute to ED – an unfortunate side effect.

One of the medications known to cause sexual dysfunctions is gabapentin

What Is Gabapentin? 

Gabapentin is an anticonvulsant medication often used by those with epilepsy to help control seizures. But gabapentin is also sometimes used to treat restless leg syndrome and other forms of nerve pain. 

Gabapentin alters electrical activity in the brain and influences the actions of neurotransmitters, which are responsible for carrying messages throughout the nervous system. The most popular branded forms of gabapentin include Horizant, Neurontin, and Gralise. Each of these medications are available as a liquid, capsule, and tablet. 

Why Is It Used? 

Gabapentin is an effective way to prevent and control seizures. By slowing or relaxing activity in the brain, gabapentin is able to reduce the frequency of seizures, along with their intensity. There is no age restriction for this drug; both adults and children with epilepsy are eligible to take it. 

Gabapentin is also sometimes used as a way to reduce the burning or stabbing sensation known as post-herpetic neuralgia, which is a common symptom of shingles. When oral gabapentin was taken at a daily dose of 1,200 milligrams, it reduced even severe levels of nerve pain commonly associated with shingles and diabetes. One study from 2016 suggested that a mixture of gabapentin and oxycontin, an opioid painkiller, might be an effective method of pain treatment that can improve the overall quality of life for those with severe pain stemming from cancer. As of now this is not a common practice. Horizant is an extended release gabapentin that has been used to treat restless leg syndrome

What Are Possible Side Effects of Gabapentin? 

Alongside erectile dysfunction, gabapentin can cause other side effects. A 2017 data review found these effects were more common in people taking gabapentin than in those taking a placebo. 

The most common side effects, occurring in roughly 10% of those taking gabapentin, include:

  • Fever
  • Difficulty speaking
  • Dizziness
  • Hostility
  • Jerky movements
  • Nausea and vomiting
  • Problems walking
  • Sleepiness
  • Viral infection
  • Water retention (swelling in the arms, hands, feet, and legs)

Children or older adults taking gabapentin are more susceptible to adverse reactions. Some of the less common but possible side effects of gabapentin include:

  • Blurry vision
  • Bruising
  • Chest or back pain
  • Chills
  • Constipation
  • Coughing
  • Diarrhea
  • Dry mouth and hoarseness
  • Fatigue
  • Flu or cold like symptoms
  • Increased appetite and weight gain
  • Memory loss
  • Mood changes
  • Mouth ulcers
  • Shortness of breath
  • Sore throat and swollen glands
  • Trembling
  • Uncontrollable eye rolling
  • Upset stomach
  • Urinary problems
  • Vomiting
  • Weakness

In addition to these side effects, gabapentin coupled with the following substances may create further negative side effects:

  • Caffeine
  • Ethacrynic acid, a diuretic
  • Losartan, a medication used to treat high blood pressure
  • Magnesium oxide, a mineral supplement and antacid
  • Mefloquine, an antimalarial drug
  • Morphine, an opioid pain medication
  • Phenytoin, another anti seizure medication

What is the Typical Dosage of Gabapentin? 

Several factors affect someone's gabapentin dosage, and the prescribing doctor will take into account the patient’s age, weight, overall health, and kidney function when figuring out the right dose. The delivery type, medical condition, and brand of gabapentin can sometimes play a role in dictating dose too. 

The number of daily doses, frequency of doses, and duration that a person will be required to take gabapentin will vary from person to person. As an oral capsule, gabapentin is available in a wide variety of sizes, including 100 mg, 300 mg, 400 mg, and 800 mg doses. Daily dosage can vary from as low as 200-300 mg/day to 1800 mg/day, and gabapentin has been studied as high as 3600 mg/day.

Sexual dysfunctions have been reported as a side effect of gabapentin doses as low as 300 mg daily.

How Can You Treat Gabapentin-Induced Erectile Dysfunction?

As a result of taking gabapentin, it’s possible for a few different sexual health issues to arise.

Some older men have lost the ability to orgasm while taking this prescription medication. While this severe symptom is a pretty rare occurrence, a much more common side effect is erectile dysfunction.

It’s important to talk with the doctor who prescribed your gabapentin about any possible side effects that you're experiencing. There may be alternatives to gabapentin that can treat your underlying condition. Additionally, your physician may be able to write another prescription to help with the erectile dysfunction while remaining on gabapentin.

The benefits of gabapentin are critical to many patients, so don't plan to cut it out without consulting your physician, even if you are experiencing erectile dysfunction. 

How can you treat ED related to gabapentin?

Prescription Medication 

The first step if you're experiencing erectile dysfunction is to talk with your gabapentin-prescribing doctor about changing treatment or whether your dose can be reduced. If this is not possible, it may make sense to discuss using a PDE5 inhibitor to help with erection issues. 

These oral medications are the most common medical treatment for erectile dysfunction, as they help improve blood flow to the penis and are incredibly effective for most guys who try them. The FDA has approved the following medications for erectile dysfunction treatment: Viagra® (sildenafil), Cialis® (tadalafil), Levitra® (vardenafil), and Stendra® (avanafil). 

These medications all work by the same mechanism of action and have been around for twenty years. Millions of men have found successful relief from ED, they're cheap, and they're now easier to get with the help of telemedicine providers like Rex MD.

Sildenafil (Viagra) remains the most popular ED treatment on the market, and it's typically taken about an hour or so before sexual activity is expected. Tadalafil is known for its longer action, working for as long as 36 hours after taking it, and it can even be prescribed in a low daily dosage, to be taken once-daily.

These drugs will not work unless you're sexually aroused. In other words, PDE5 inhibitors work with your normal erectile response, they don't create erections spontaneously. These medications are generally effective in 7 out of 10 men, but the rates are lower for diabetic and cancer patients. 

You should not take any of these medications if you are currently also taking nitrates for a cardiovascular condition. The most common side effects of PDE5 inhibitors include:

  • Headache
  • Stuffy nose
  • Facial flushing
  • Muscle aches
  • indigestion

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Vacuum Erection Devices (Penis Pumps) 

Vacuum erection devices are an alternative option for men that can not take PDE5 inhibitors for whatever reason. This method involves a plastic cylinder that slides over the penis, creating a vacuum seal around the penis. A manual or electric vacuum pump then forms a low pressure vacuum in the cylinder around the penis, pulling blood into the penis and creating an erection. Once an erection has been achieved, an elastic ring is slipped around the base of the penis, ensuring blood stays in the penis. 

The penis should stay full of blood, and erect until the ring is removed. The ring should not be used for longer than 30 minutes. With proper use, the vacuum erection devices are typically effective for three out of four men. 

Self Injection Therapy 

Using a fine needle, this treatment involves injecting a drug called alprostadil directly into the side of the penis. When starting out with this treatment, it’s best to have the first one performed at a doctor’s office to learn the correct procedure. This approach has the highest rate of success, with roughly 85% of users reporting a successful erection. It's also the least comfortable for most men, for obvious reasons.

Self-injection therapy typically produces an erection that's firm enough for sex, but the effects fade after 20 or 30 minutes or after climax has been achieved. Because self-injection therapy involves circumventing the penile nerves, it's possible to maintain an erection even after orgasm. In fact, a long erection is the most common side effect reported with this particular treatment. A prolonged erection, known as priapism, might require a second injection of an antidote to reduce.

The Takeaway: Gabapentin is a common medication used to treat seizures, but one of the side effects can be erectile dysfunction. Depending on a few factors, the best way to treat ED from gabapentin is either by changing or reducing the medication, using a PDE5 inhibitor like Viagra or Cialis, a vacuum erection device, or self-injection ED therapy.

Erectile dysfunction is a common side effect of gabapentin, and the conditions that gabapentin treats are typically much more serious than dealing with sexual dysfunctions. It’s important to keep taking the medication if your doctor suggests it.

Plus, there are plenty of highly effective options for treating the erectile dysfunction that gabapentin can cause. Rex MD may be able to help, with licensed clinicians ready to help determine if ED meds are right for you. Start your online consultation by clicking here.