Adenosine A1 antagonist (CBZ effect)
Adenosine A1 receptor antagonist (carbamazepine effect)
- Not wake-promoting: caffeine’s arousal is an A2A effect, not A1
- Chronic exposure upregulates A1 receptors, a compensatory swing
- The resulting rise in A1 signaling is a proposed antimanic mechanism, not an established one
- Carbamazepine blocks adenosine A1 receptors — the same receptor action as caffeine
- Acutely that is pro-epileptic: A1 blockade enhances excitatory transmission onto hippocampal CA1 pyramidal cells at therapeutic concentrations, with no matching change in inhibition
- Chronic dosing runs the other way — persistent upregulation of brain adenosine receptors after chronic carbamazepine (1987)
- In astrocyte culture the upregulation appears only where basal A1 is low, and brings a coupling to phospholipase C that was not there before (1999)
- The evidence is not uniform: oral carbamazepine had no major effect on mouse brain A1 receptors (1991), and chronic carbamazepine down-regulates A2 receptors
- A net rise in A1 signaling is a proposed antimanic mechanism — a hypothesis, not a demonstrated pathway. The receptor papers make no such claim
Drugs with this mechanism (4)
- Carbamazepine — Anticonvulsant/mood stabilizer and potent autoinducer; HLA-B*1502 rash risk.
- Carbamazepine ER capsules — Bead-filled extended-release carbamazepine capsule that can be opened and sprinkled.
- Carbamazepine ER (Equetro) — Carbamazepine ER capsule - the only carbamazepine approved for acute bipolar mania.
- Carbamazepine XR — Extended-release carbamazepine for seizures and trigeminal neuralgia; potent enzyme inducer.
All mechanisms · Open Adenosine A1 antagonist (CBZ effect) in the interactive console ↗