My Quora Answer to: "Why when I had withdrawal from gabapentin my skin itch that felt like bugs for crawling all over me?"
You are hallucinating.
Gabapentin withdrawal resembles the symptoms of alcohol and benzodiazepine withdrawal because they all act on gamma-aminobutyric acid, or GABA, an inhibitory brain neurotransmitter. Release the inhibition (stop taking the drug) and you increase brain excitation.
Several medications and illicit drugs can lead to physical dependence in people who use them for a longer period of time. A person’s body adapts to it and essentially "expects" a substance to be present and will rely on it to function normally. This is physiological dependency, which is not the same as addiction. Addiction involves a compulsion to seek out the drug and use it, negatively interfering with other areas of the person’s life.
When a dependent person stops taking the drug or drastically reduces the amount of the drug used on a regular basis, they can experience withdrawal.
Withdrawal can also cause "formication," or the feeling that ants are crawling over their skin. Itching is prominent. The name comes from the Latin word “formica,” which means ant. It is a tactile hallucination, meaning that a person feels a physical sensation without a physical cause. Feeling sensations on the skin with no physical stimulation is called a "paresthesia." Other paresthesias include sensations of burning, tingling, numbness, and cold.
Formication due to drug withdrawal is usually temporary and should resolve when a person recovers from withdrawal.