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Gabapentin side effects

by egpat         22 May 2024

Gabapentin is a well-known drug with the brand name Neurontin. This is one of the medications that belongs to the category of anti-epileptic drugs. But what are the important side effects of this medication? What is its effect on different organs? How does it produce side effects? How does it interact with other drugs? All these things will be discussed in this article.

Before we see the important side effects of this medication, let us see the clinical use of this drug. Gabapentin is an anti-epileptic drug, so it can be used in the treatment of partial-onset seizures. At the same time, this medication can also be used for other conditions like neuropathic pain, and it can even be used to control the pain in post-herpetic neuralgia. Finally, this drug can also be indicated for the treatment of restless leg syndrome (RLS).

In this way, gabapentin mainly inhibits neuronal activity, so it can be used as an analgesic, an antiepileptic, or to reduce excitation. Whatever the use, this is one of the most widely used medications, so it is very essential to know the important side effects and how they should be managed. So let's start our discussion on the different side effects of gabapentin.

1. Breathing problem

Gabapentin mainly acts as a CNS depressant. It does not have a direct effect on the lungs, but when it is combined with other CNS depressants like opioids, it can produce some respiratory depression. Since opioids can directly produce respiratory depression, the combination of gabapentin and opioids can produce some severe respiratory depression.

Many times, opioids may be combined with antiepileptic agents to control the pain. For instance, morphine is one of the opioids that can be used as an analgesic. When this morphine is combined with gabapentin, it can produce respiratory depression. Not only opioids, but a few other drugs, like anti-anxiety drugs like benzodiazepines or antihistamines, can also produce respiratory depression when they are combined with gabapentin.

The use of gabapentin should be carefully monitored if a few symptoms, like shortness of breath, trouble breathing, or breathlessness, are observed. In people with any previous history of respiratory disorders, such as COPD (chronic obstructive pulmonary disorder), gabapentin can increase respiratory risk. This respiratory side effect is more pronounced in the elderly.

2. Central depression

Since gabapentin is a CNS depressant, it can produce a variety of symptoms, including increased dizziness, sleepiness, and drowsiness in people. It can even increase tiredness and unexpected weakness. People may have a few of the speech problems and may find some difficulty with speech. These side effects are common with many of the anti-epileptic drugs that produce CNS depression.

When gabapentin is combined with alcohol, these central side effects are more pronounced. That's why it is recommended that a high intake of alcohol be avoided with gabapentin. Similarly, many of the CNS depressants, like sleeping pills and antianxiety medication, should be carefully used with gabapentin. Along with the dizziness and drowsiness, gabapentin can also produce blurred vision and double vision.

3. Gastric effects

Use of gabapentin can produce a few of the gastric effects, like diarrhea. However, sometimes it can also produce some constipation. Diarrhea is the most common side effect observed in many people. It can also produce some dry mouth, nausea, and vomiting.

With the use of gabapentin, few of the essential body fluids are lost either by diarrhea or by vomiting. Therefore, whenever oral contraceptives are used along with gabapentin, they may be lost from the body. This results in their loss of contraceptive action.


4. Dehydration

Dehydration is another effect of gabapentin. It can result in dark stools and smelly stools. This is because of the loss of body fluids due to dehydration. In a few people, this dehydration may be combined with diarrhea. In such conditions, plenty of fluids and water should be taken to restore the body's fluids.

5. Changes in memory

Gabapentin acts on the brain and depresses the central nervous system. Therefore, it can impair memory. It can produce amnesia, a temporary loss of memory, which may be observed within the first few weeks of the treatment.

6. Weight gain

This is another important side effect of gabapentin. This medication can increase appetite in people, so it can increase food intake, which may result in weight gain. That's why, while using gabapentin, you should take a balanced diet and avoid high-calorie diets and fatty foods in order to control weight gain.

7. Mood changes

This is particularly observed in children aged 3 to 12 years. In those people, the use of gabapentin can produce a variety of mood changes resulting in hyperactivity, thought disorders, aggressiveness, and even suicidal thoughts. So in such an age group of people, gabapentin should be carefully used, and any abnormal changes in the mood should be thoroughly monitored.

8. Motor effects

Gabapentin can produce some motor side effects. One of the most important is ataxia, which leads to a loss of muscle control in the arms and legs. Motor incoordination can be observed, which may result in some jerky movements and even some loss of balance. In a few people, gabapentin can also produce some tremors and shakiness.

9. Addiction symptoms

Gabapentin is an addictive drug, so it should not be stopped suddenly. Instead, it should be slowly tapered in order to avoid any withdrawal side effects. It can cause withdrawal symptoms like increased anxiety, insomnia, lack of sleep, excessive sweating, palpitations, or an excessive heartbeat. If these symptoms are observed, it may indicate some addiction to gabapentin. That's why high doses of gabapentin should be avoided, and even the dose of gabapentin should not be suddenly stopped in order to avoid withdrawal effects.

10. Effects of antacids

Antacids can interfere with gabapentin, so when they are combined with this medication, they can reduce its absorption. Particularly, antacids containing aluminum and magnesium salts may form a complex with gabapentin and thereby reduce its absorption. That's why antacids should not be combined with gabapentin, and if it is required, gabapentin can be taken after 2 hours of administration of antacids.


The main side effect of gabapentin is CNS depression, which results in drowsiness and sleepiness, which are further enhanced by other CNS depressants and alcohol. Even this medication can cause breathing problems when it is combined with drugs like opioids, antihistamines, and other CNS depressants. Weight gain, blurred vision, mood changes, temporary loss of memory, and blurred vision are a few of the other important side effects of gabapentin. But many of the side effects are well tolerated, and drowsiness is the most common side effect that can be observed in many people.