Gabapentin is an anticonvulsant drug prescribed for individuals suffering from epilepsy. Its main function is controlling seizures. Another common use for this drug is the treatment of postherpetic neuralgia, which is an intense pain in the nerves that may occur after a shingles infection. Additionally, the drug is used for treating a condition known as restless legs syndrome.
The drug is often marketed under these brand names: Neurontin, Gralise, Gaborone, FusePaq Fanatrex, and Horizant.
As with any prescription drug, gabapentin does have some side effects. Let’s explore them further.
How does gabapentin work?
This drug may have more than one mode of action, and researchers have not pinpointed the exact mechanism. One explanation is that the drug influences the levels of gamma-aminobutyric acid (GABA) in the brain. GABA is a neurotransmitter, which is a molecule that helps neurons (brain cells) communicate with each other. GABA is known to have a calming effect — the more GABA is present in the brain, the less activity there is on the neurons.
When gabapentin enhances the levels of GABA, it contributes to a decrease in neuronal activity. In turn, seizures are calmed down and nerve pain is reduced.
Another mode of action based on other studies is the blocking of calcium channels by molecules of gabapentin. These calcium channels are involved in pain reception. When the drug binds to them, transmission of pain signals is blocked, in turn relieving nerve pains.
What are the side effects of gabapentin?
This drug produces a number of mild side effects. According to one study in 2017, around 10% of participants who took this drug experienced these side effects:
- Sleepiness
- Dizziness
- Swelling of the arms, hands, legs, and feet due to water retention
- Difficulty walking
Children and seniors are more vulnerable to these side effects than others.
Aside from these, the drug also has a range of less common side effects, such as:
- Chest pain
- Back pain
- Diarrhea
- Constipation
- Vomiting
- Upset stomach
- Blurry vision
- Increased appetite
- Weight gain
- Mood changes
- Bruising
- Chills
- Fatigue
- Cough
- Fever
- Flu-like symptoms
- Dry mouth
- Memory loss
- Shortness of breath
- Sore throat
- Mouth ulcers
- Urinary problems
- Uncontrollable eye rolling
- Weakness
- Trembling
In children, the following adverse effects may also show up:
- Lack of concentration
- Hyperactivity
- Behavioral problems
- Anxiety
- Depression
- Changes in mood
- Subpar performance at school
Does gabapentin cause weight gain?
Weight gain is just one of the different side effects of this drug. It is not that common, affecting only about two percent of patients who are on this medication.
In some cases, gabapentin can increase your appetite, encouraging you to eat more. Increasing your food intake while not making any other lifestyle changes, like exercising more often, will most likely cause you to gain extra pounds.
In other cases, this drug will cause your body to retain more water. This extra water often accumulates in your hands, arms, legs, and feet. This condition is known as peripheral edema. As a result, the extra water will give you some extra pounds. This weight gain is not the result of fat deposits or eating more than usual.
Why can this drug make me sleepy?
Gabapentin works to calm down your neurons by decreasing the activity of nerve impulses in the brain. As a consequence, you may feel less alert and more drowsy when you take this drug.
If this happens, tell your doctor about it so he can adjust your dosage and timings. If you have to work at certain times of the day, your doctor may adjust your prescription so you take the drug only during the times when you expect to be resting.
What happens if I have trouble breathing while taking this drug?
In 2019, the FDA warned that the drug is known to cause serious breathing difficulties in those who have respiratory problems. So if you have asthma, chronic obstructive pulmonary disease (COPD), or any other respiratory condition, tell your doctor about them first before he prescribes gabapentin.
Seek medical attention right away if taking this drug triggers any breathing problems. This can turn fatal if not addressed quickly enough.
Can gabepentin trigger suicidal tendencies?
Some studies indicate that this drug may produce suicidal thoughts in some patients. Though not a common side effect, this should be taken seriously if ever it happens.
If you notice any profound changes in your mood and behavior, or you know someone who experiences these, contact a doctor right away.
Can I take this drug if I am on other medications?
Gabapentin may have adverse interactions with other drugs. Based on a 2017 study, these substances commonly interact with the drug:
- Caffeine
- Losartan (a medication for hypertension)
- Ethacrynic acid (a diuretic)
- Magnesium oxide (an antacid and mineral supplement)
- Phenytoin (another kind of seizure medication)
- Morphine (an opioid painkiller)
- Mefloquine (an antimalarial drug)
Since this drug can also cause sleepiness, talk to your doctor first if you’re taking any of these medications that also have the same side effect:
Anxiety medications- Antidepressants
- Antihistamines
- Cold and flu medications
- Narcotic pain relievers
- Sleeping pills
- Muscle relaxants
If you’re taking antacids, it’s best to avoid them within two hours of taking gabapentin. Antacids can prevent your body from properly absorbing this drug, which may lead to an accidental overdose.
In any case, it’s best to present to your doctor a complete list of the medications you’re currently on. That way, he can decide better whether to prescribe gabapentin or not.
How do I stay safe when on gabapentin medication?
The first step is to discuss your current health condition thoroughly with your doctor. Any underlying health conditions, medications you’re currently on, and even mental health issues can cause issues when taking this drug.
Once you have your prescription, follow it strictly — dosage, timing, and frequency. Do not adjust your dosage on your own. If you feel that the drug is not effective, talk to your doctor first.
Also, if you miss a dose, take it as soon as you remember. The exception is when it’s almost time to take your next dose. In that case, skip the missed dose. Avoid double dosing.
