Benzodiazepines are the class of medication used to stop a seizure in progress, and they can work in as little as one to three minutes depending on how they’re given. The most common rescue medications are midazolam (available as a nasal spray or injection) and diazepam (available as a nasal spray or rectal gel). These are considered first-line treatment for active seizures in both emergency rooms and home settings.
How These Medications Stop a Seizure
During a seizure, groups of brain cells fire uncontrollably. Benzodiazepines work by boosting the effect of GABA, your brain’s main calming chemical. Normally, GABA slows down nerve cell activity by opening tiny channels that let chloride ions flow into neurons, making them less likely to fire. Benzodiazepines don’t produce this calming signal on their own. Instead, they increase how tightly GABA binds to its receptor, amplifying the braking effect that’s already there.
The practical result: excitatory signals in the brain become less able to trigger the chain reaction that sustains a seizure. This is why benzodiazepines can halt seizure activity within minutes rather than hours.
Nasal Spray Rescue Medications
Two FDA-approved nasal sprays are designed specifically for seizure emergencies outside a hospital. Nayzilam (midazolam nasal spray) and Valtoco (diazepam nasal spray) are both approved for acute episodes of cluster seizures in people with epilepsy ages 2 and older. These are prescription medications meant to be kept on hand and administered by a caregiver when a seizure hits.
Nasal midazolam works fast. In clinical studies, it stopped seizures in an average of about 2 to 3.5 minutes after administration. One study in children found seizure control in a mean of just under 2 minutes. That speed is comparable to what hospitals achieve with IV medications, largely because nasal sprays skip the delay of finding a vein. A meta-analysis of 10 studies found that intranasal midazolam reduced the total time from hospital arrival to seizure cessation by about 3.5 minutes compared to IV or rectal options, even though the drugs themselves worked at similar speeds once administered.
Valtoco, the diazepam nasal spray, offers an alternative for people who already respond well to diazepam. It provides a more dignified and practical option compared to rectal diazepam, which was for many years the only non-IV rescue medication available.
Rectal Diazepam
Rectal diazepam gel (brand name Diastat) has been used as a seizure rescue medication for decades. It’s well absorbed and reaches peak blood levels in about 1.5 hours, though it begins working well before that peak. Studies show it typically stops seizures in about 3 to 4 minutes after administration. Dosing is weight-based: for adults and children 12 and older, the standard is 0.2 mg per kilogram of body weight, which works out to doses ranging from roughly 12.5 mg to 20 mg depending on size.
The main drawback is the route itself. Administering a rectal medication during a seizure can be difficult and uncomfortable, especially in public settings or for older children and adults. This is a major reason nasal sprays have become preferred when available.
Buccal Midazolam
Buccal midazolam is a liquid placed between the gums and cheek, where it absorbs directly into the bloodstream through the lining of the mouth. It’s widely used in the UK and other countries as a home rescue option. The key to proper administration is placing the solution against the inner cheek rather than swallowing it, since absorption through the gut is slower and less reliable. This route is particularly common for children, as it’s relatively easy for a caregiver to administer during a seizure.
What Hospitals Use
In an emergency department, IV lorazepam is considered the gold standard. It begins working within 1 to 3 minutes after injection, and IV medications in general have the fastest onset because they enter the bloodstream directly. IV midazolam and IV diazepam are also used, with peak blood levels reached in 90 to 150 seconds.
The catch is that starting an IV takes time, especially on someone who is actively seizing. A large clinical trial found that intramuscular midazolam given by paramedics actually outperformed IV lorazepam in real-world conditions, not because the drug was better, but because it could be given faster without the delay of placing an IV line. This is the same principle that makes nasal sprays so effective outside the hospital: speed of administration matters as much as speed of the drug itself.
When a Seizure Becomes an Emergency
A seizure lasting 5 to 10 minutes or longer is classified as status epilepticus, a medical emergency that requires immediate treatment. Repeated seizures without the person returning to normal consciousness between episodes also qualify. Brain injury risk increases the longer a seizure continues, which is why neurologists emphasize rapid medication delivery. Benzodiazepines are the established first-line treatment, and multiple studies confirm they should be given as early as possible rather than waiting to see if the seizure stops on its own.
Risks of Rescue Medications
The most significant risk with benzodiazepines is slowed breathing. In one study of 57 prolonged seizure episodes treated with benzodiazepines, respiratory depression occurred in 14% of cases. The risk climbed sharply when multiple doses were given: six of the eight cases involving breathing problems followed repeat dosing. This is why rescue medication instructions typically specify a single dose and advise calling emergency services if the seizure doesn’t stop.
Drowsiness after the seizure resolves is expected and not a cause for concern on its own. The person should be placed on their side to keep the airway clear, both during and after the event. Caregivers prescribed a rescue medication should be trained in advance on proper dosing, timing, and what to watch for afterward.
Choosing the Right Rescue Medication
The best rescue medication depends on what’s practical for your situation. Nasal sprays are the easiest to administer and work just as fast as IV options in real-world conditions. Rectal gel remains effective but is less convenient. Buccal midazolam offers a middle ground where nasal formulations aren’t available. All three routes are significantly faster than waiting for emergency services to arrive and start an IV.
Your neurologist will prescribe a specific medication and dose based on age, weight, seizure type, and what other medications are already being taken. Having a seizure action plan that includes the rescue medication, the correct dose, and clear instructions for when to call 911 makes a critical difference in how quickly and safely a seizure can be treated.