1. Introduction
Pregabalin is an anticonvulsant and analgesic medication used to manage neuropathic pain, epilepsy, and generalised anxiety disorder (GAD). It works by modulating calcium channel activity in nerve cells, reducing the release of excitatory neurotransmitters and alleviating pain or seizures. Pregabalin is often chosen for its efficacy and relatively mild side effect profile.
2. Indications
- Neuropathic pain (e.g., diabetic peripheral neuropathy, postherpetic neuralgia)
- Fibromyalgia
- Generalised anxiety disorder (GAD)
- Adjunctive therapy for partial seizures in epilepsy (with or without secondary generalisation)
- Neuropathic pain associated with spinal cord injury
3. Dosage
Adults:
- Neuropathic pain: Start with 75 mg twice daily (150 mg/day); increase to 150 mg twice daily (300 mg/day) if necessary after 3–7 days. Maximum dose: 600 mg/day.
- Epilepsy (adjunctive therapy): Start with 75 mg twice daily; increase to 150 mg twice daily after 1 week if tolerated. Maximum dose: 600 mg/day.
- Fibromyalgia: Start with 75 mg twice daily; titrate to 150 mg twice daily if needed. Maximum dose: 450 mg/day.
- Generalised anxiety disorder (GAD): Start with 75 mg twice daily; increase to 300–450 mg/day based on response.
Elderly:
- Start with lower doses due to decreased renal clearance. Adjust based on renal function.
Renal Impairment:
- Creatinine clearance (CrCl) 30–60 mL/min: 75–300 mg/day in divided doses.
- CrCl <30 mL/min: 25–150 mg/day in divided doses.
4. Administration
- Take orally with or without food.
- Doses should be taken at evenly spaced intervals (e.g., twice daily).
- Do not abruptly discontinue, as this may lead to withdrawal symptoms or increased seizure frequency.
5. Forms Available
- Capsules: 25 mg, 50 mg, 75 mg, 100 mg, 150 mg, 200 mg, 300 mg
- Oral solution: 20 mg/mL
6. Side Effects
6.1 Common Side Effects:
- Dizziness
- Drowsiness
- Dry mouth
- Blurred vision
- Weight gain
6.2 Less Common Side Effects:
- Peripheral oedema
- Euphoria
- Constipation
- Fatigue
6.3 Rare but Serious Side Effects:
- Suicidal thoughts or behaviour
- Angioedema (swelling of the face, tongue, or throat)
- Severe allergic reactions
- Myopathy or rhabdomyolysis
7. Warnings
- CNS Effects: Pregabalin can cause sedation, dizziness, and impair concentration, increasing the risk of falls, particularly in elderly patients.
- Suicidal Ideation: Monitor for behavioural changes, depression, or suicidal thoughts, especially during the initial weeks of therapy.
- Substance Misuse: Pregabalin has potential for abuse due to its euphoric effects. Use cautiously in patients with a history of substance misuse.
8. Precautions
- Avoid abrupt discontinuation to reduce the risk of withdrawal symptoms, including insomnia, headache, or increased seizure frequency.
- Use cautiously in patients with renal impairment or heart failure, as pregabalin can cause peripheral oedema.
- Monitor for weight gain, especially in patients with diabetes.
9. Interactions
- CNS depressants (e.g., opioids, benzodiazepines): Increased risk of sedation and respiratory depression.
- Thiazolidinediones (e.g., pioglitazone): Increased risk of peripheral oedema.
- Alcohol: Enhances CNS depressant effects. Avoid concurrent use.
10. Monitoring Parameters
- Assess for reduction in pain severity or seizure frequency.
- Monitor renal function, especially in elderly or renally impaired patients.
- Observe for behavioural changes, such as suicidal ideation or mood changes.
- Monitor for signs of peripheral oedema or significant weight gain.
11. Use in Children
- Not approved for use in children below 18 years for most indications, as safety and efficacy data are limited.
12. Use in Pregnancy
- Category C: Use only if the potential benefit justifies the risk to the foetus. Animal studies show potential risks, but human data are limited.
- Pregabalin is excreted in breast milk; avoid use during breastfeeding unless necessary.
13. Use in Elderly
- Use cautiously due to increased risk of sedation, dizziness, and falls. Dose adjustments are often needed due to reduced renal clearance.
14. Use in Kidney Disease
- Adjust doses based on creatinine clearance (see dosage recommendations).
- Monitor renal function periodically in long-term therapy.
15. Use in Liver Disease
- No specific dose adjustment required, as pregabalin is minimally metabolised by the liver.
16. Patient Counselling Points
- Take pregabalin exactly as prescribed, at the same time each day.
- Avoid driving or operating machinery until you know how the medication affects you, as dizziness and drowsiness are common.
- Do not stop taking pregabalin abruptly without consulting your doctor.
- Inform your doctor of any swelling, unusual weight gain, mood changes, or suicidal thoughts.
- Avoid alcohol while taking pregabalin, as it may increase drowsiness and dizziness.
17. Table of Brand Names, Manufacturer, and Prices in USD
Brand Name | Manufacturer | Strength/Dosage Form | Price (USD) |
---|---|---|---|
Lyrica | Pfizer | 75 mg Capsule | $150 (30 capsules) |
Generic Pregabalin | Various | 75 mg Capsule | $40 (30 capsules) |
Lyrica CR | Pfizer | 165 mg Extended-Release Tablet | $200 (30 tablets) |
18. 15 FAQs (Frequently Asked Questions)
1. What is Pregabalin used for?
Pregabalin is used to treat neuropathic pain, epilepsy, fibromyalgia, and generalised anxiety disorder.
2. How does Pregabalin work?
It reduces nerve activity by modulating calcium channels, decreasing the release of excitatory neurotransmitters.
3. Can Pregabalin cause weight gain?
Yes, weight gain is a common side effect, often due to fluid retention and increased appetite.
4. Is Pregabalin addictive?
Pregabalin has potential for misuse or dependency, particularly in patients with a history of substance abuse.
5. How long does Pregabalin take to work?
Pain relief or seizure reduction may occur within a few days, but full effects can take up to 2–4 weeks.
6. Can Pregabalin cause drowsiness?
Yes, drowsiness and dizziness are common side effects. Avoid activities requiring alertness until you know how it affects you.
7. Can I stop Pregabalin abruptly?
No, stopping suddenly may cause withdrawal symptoms or worsen seizures. Taper the dose gradually under medical supervision.
8. Is Pregabalin safe during pregnancy?
Pregabalin should only be used during pregnancy if the benefits outweigh the risks.
9. Can Pregabalin interact with alcohol?
Yes, alcohol can increase the sedative effects of pregabalin, leading to excessive drowsiness or dizziness.
10. What is the maximum dose of Pregabalin?
The maximum dose is 600 mg/day, divided into two or three doses.
11. Can Pregabalin be taken with food?
Yes, pregabalin can be taken with or without food.
12. Does Pregabalin cause swelling?
Yes, peripheral oedema (swelling of the legs or hands) is a possible side effect.
13. Can Pregabalin be used for anxiety?
Yes, pregabalin is approved for the treatment of generalised anxiety disorder (GAD).
14. How should Pregabalin be stored?
Store at room temperature, away from moisture and heat.
15. Is Pregabalin a first-line treatment for neuropathic pain?
Yes, it is often recommended as a first-line treatment for conditions like diabetic neuropathy and postherpetic neuralgia.