The term “acid” refers to two distinct concepts when considering seizure risk: the recreational drug lysergic acid diethylamide (LSD) and the physiological condition of imbalanced blood pH known as acidosis. A seizure is a sudden, uncontrolled electrical disturbance in the brain that causes changes in behavior, movements, or consciousness. This article explores the connections between both forms of “acid” and the potential for seizure activity, which differ significantly in their causes and mechanisms.
LSD and Acute Seizure Risk
Lysergic acid diethylamide (LSD) is a potent hallucinogen acting primarily on the brain’s serotonin system. A direct pharmacological link between pure LSD and seizure induction is rare compared to other illicit substances like cocaine or methamphetamine. However, seizures can occur through both direct and indirect mechanisms.
LSD acts as an agonist on the serotonin 5-HT2A receptor, which is widely distributed in the cerebral cortex and regulates neuronal excitability. Excessive stimulation of this receptor can theoretically increase brain excitability, lowering the seizure threshold in susceptible individuals.
More commonly, seizures are triggered by indirect physiological consequences of a severe drug reaction. A “bad trip” can cause extreme agitation, panic, and a hypertensive crisis, which may provoke a seizure. Severe agitation or Serotonin Syndrome can also lead to hyperthermia (dangerously elevated body temperature), a known seizure trigger that can cause multi-organ failure. Additionally, street-bought LSD may contain adulterants, such as synthetic cathinones, which are far more likely to cause convulsions than pure LSD.
Differentiating Seizures from Other Drug-Induced Neurological Events
The acute neurological effects of serotonergic drugs can often be mistaken for a true seizure, making accurate observation important. A classic generalized tonic-clonic seizure involves loss of consciousness followed by rhythmic, sustained muscle contractions. The episode typically lasts only a few minutes, after which the person is confused and drowsy.
Serotonin Syndrome
A severe drug reaction may manifest as muscle rigidity or myoclonus (sudden, involuntary muscle jerks) that are not rhythmic or sustained. Serotonin Syndrome, caused by excessive serotonin activity, includes a triad of symptoms: altered mental status, autonomic instability (high heart rate and blood pressure), and neuromuscular hyperactivity. This hyperactivity, including muscle rigidity and twitching, can be confused with seizure activity.
Acute Dystonic Reaction
Another non-seizure event is an acute dystonic reaction, involving continuous, painful muscle spasms that result in twisting or abnormal postures. This reaction is often associated with dopamine-blocking drugs. The key distinguishing factor is that the person typically remains conscious during a dystonic episode, unlike during a generalized seizure.
How Metabolic Acidosis Can Trigger Seizures
The second meaning of “acid” relates to metabolic acidosis, a serious medical condition where the blood’s pH drops below the normal range (7.35 to 7.45) due to the accumulation of acid or loss of bicarbonate. Although localized brain acidosis often helps stop a seizure, systemic metabolic acidosis from an external cause can increase seizure risk.
Metabolic acidosis frequently occurs during severe systemic illness, such as uremic encephalopathy from kidney failure or specific drug poisonings like massive salicylate or methanol overdose. The accumulation of toxic organic acids in the bloodstream disrupts the delicate balance of ions and neurotransmitters in the central nervous system.
Severe uremia, for instance, causes the build-up of waste products and electrolyte disturbances, contributing to neuronal dysfunction and hyperexcitability. This profound metabolic derangement lowers the overall seizure threshold. The seizure is not caused by the low pH alone, but by the underlying systemic pathology that simultaneously causes the acidosis.
Emergency Response to Seizures
If someone experiences a seizure, the immediate response must focus on safety, regardless of the suspected cause.
The following steps should be taken:
- Protect the individual from injury by clearing the area of hard or sharp objects.
- Place something soft and flat, like a jacket or cushion, beneath their head.
- Do not attempt to restrain the person or put anything into their mouth, as this risks injury or choking.
- Start timing the seizure immediately; most seizures last less than two minutes.
- Gently turn the person onto their side once the convulsive movements have stopped to help keep the airway clear.
Call emergency services immediately if the seizure lasts more than five minutes, if the person is injured, if they have difficulty breathing afterward, or if this is their first known seizure. Remain with the person until they regain full awareness, offering calm reassurance.