Can Magnesium Be Used With Gabapentin?
Yes, magnesium can be used concurrently with gabapentin, but magnesium-containing antacids reduce gabapentin absorption by approximately 20% and should be separated by at least 2 hours. 1
Key Drug Interaction: Antacids Containing Magnesium
- Antacids containing magnesium and aluminum hydroxides (such as Maalox®) reduce gabapentin bioavailability by about 20% when taken simultaneously. 1
- This decrease in bioavailability drops to approximately 10% when gabapentin is administered 2 hours after the magnesium-containing antacid. 1
- To maintain therapeutic gabapentin levels, administer gabapentin at least 2 hours after any magnesium-containing antacid. 1
Intravenous Magnesium as Adjuvant Therapy
- Intravenous magnesium has been used successfully in combination with other agents for neuropathic pain management, though not specifically studied with oral gabapentin. 2
- A case series demonstrated that intravenous magnesium (1.2 g) combined with lidocaine provided sound pain relief in nine patients with intractable trigeminal neuralgia, with only mild transient dizziness reported. 3
- N-methyl-D-aspartate receptor antagonists like magnesium are administered alone or in combination with other analgesics (including gabapentinoids) to improve analgesic effect in multimodal pain management. 2
Clinical Context for Magnesium-Gabapentin Interaction
- The interaction between magnesium-containing antacids and gabapentin is pharmacokinetic (absorption-related) rather than pharmacodynamic, meaning it affects how much drug enters the bloodstream, not how the drugs work together. 1
- Research has identified magnesium oxide as one of the main substances that interacts with gabapentin, though the clinical significance varies by formulation and timing. 4
- Gabapentin has a favorable drug interaction profile overall, with limited interactions compared to traditional antiepileptic drugs. 5, 6
Practical Recommendations
- If using oral magnesium supplements or magnesium-containing antacids, separate administration from gabapentin by at least 2 hours to minimize absorption interference. 1
- Intravenous magnesium used as part of multimodal analgesia does not have the same absorption interaction and can be considered as an adjuvant to gabapentin therapy. 2, 3
- Monitor for adequate pain control when initiating magnesium supplements in patients already on gabapentin, as reduced absorption may necessitate gabapentin dose adjustment. 1
- The timing separation applies to all gabapentin doses throughout the day, as gabapentin requires three-times-daily dosing due to its saturable absorption pharmacokinetics. 7, 8