From the Guidelines
Muscle relaxers can potentially lower seizure threshold, increasing the risk of seizures in susceptible individuals, with buspirone being a specific agent that can lower seizure threshold 1. When considering the relationship between seizure threshold and muscle relaxants, it is essential to weigh the potential risks and benefits.
- Muscle relaxers, such as neuromuscular blockers (e.g., cisatracurium, atracurium, rocuronium, and vecuronium), are not directly associated with lowering seizure threshold 1.
- However, other agents like buspirone, which can be used as an adjunct to prevent shivering, may lower seizure threshold 1.
- The mechanism behind this interaction involves the effects of these medications on central nervous system inhibitory pathways, particularly GABA neurotransmission, which can disrupt the balance between excitatory and inhibitory signals in the brain.
- It is crucial to exercise caution when prescribing muscle relaxers to patients with seizure risk, starting with lower doses and monitoring closely for any neurological changes.
- Coordination between neurologists and primary care providers is essential to optimize medication management and minimize risks for patients requiring both seizure control and muscle relaxation.
- Additionally, the use of sedatives, such as ketamine and propofol, may have conflicting evidence regarding their effects on neurotoxicity and neuroprotection, highlighting the need for careful consideration in patients with seizure risk 1.
From the Research
Relationship Between Seizure Threshold and Muscle Relaxants
- The relationship between seizure threshold and muscle relaxants is not directly addressed in the provided studies, but there is evidence suggesting that certain medications, including some muscle relaxants, can affect seizure threshold 2, 3, 4.
- A case report describes the delayed onset of rocuronium, a nondepolarizing muscle relaxant, in a patient taking levetiracetam for epilepsy, suggesting that patients with intractable epilepsy taking levetiracetam may have resistance to rocuronium 2.
- Psychotropic drugs, including some muscle relaxants, may lower seizure threshold, with the risk of seizures being dose-dependent and influenced by individual factors such as inherited seizure threshold and presence of seizurogenic conditions 3.
- Modafinil and armodafinil, classified as psychostimulants, have been associated with a small risk of seizures, but may also have anticonvulsant effects in certain situations 4.
Factors Influencing Seizure Threshold
- Seizure threshold can be influenced by various factors, including age, gender, anesthetic drugs, concurrent psychotropics, and morphological characteristics 5.
- Repetitive transcranial magnetic stimulation (rTMS) has been shown to lower seizure threshold in patients undergoing electroconvulsive therapy (ECT) 6.
- The use of certain medications, including muscle relaxants, can affect seizure threshold, and individualized decisions should be made when considering their use in patients with seizure disorders 3, 4.