Yes, Terbutaline Can Cause Muscle Twitches and Tremor
Terbutaline causes tremor as a well-established and common side effect through beta-2 adrenergic receptor activation, occurring in up to 38% of patients at standard doses. 1
Mechanism of Action
Terbutaline produces muscle tremor through beta-adrenergic receptor activation and the β-adrenergic receptor/cAMP/PKA pathway, which increases intracellular calcium cycling in skeletal muscle. 2 This mechanism is distinct from true fasciculations seen with cholinesterase inhibitors—terbutaline causes rhythmic muscle contractions (tremor) rather than spontaneous motor unit depolarization. 2
Clinical Evidence and Incidence
The FDA-approved drug label provides clear data on tremor incidence from controlled trials:
- At 0.25 mg subcutaneous dose: 7.8% of patients experienced tremor 1
- At 0.5 mg subcutaneous dose: 38% of patients experienced tremor 1
- Tremor is dose-dependent and transient, usually not requiring treatment 1
Comparative studies demonstrate that two trials specifically reported more frequent tremor with terbutaline when compared to epinephrine in the treatment of acute asthma. 3
Additional Neurological Side Effects
Beyond tremor, terbutaline causes other neurological effects including:
Route-Specific Considerations
Intravenous terbutaline produces more pronounced tremor than inhaled administration. Research shows that IV doses exceeding therapeutic levels more than doubled skeletal muscle tremor, while inhaled terbutaline produced equivalent bronchodilation without significant tremor. 5 This suggests that inhaled routes minimize systemic exposure and reduce tremor risk while maintaining therapeutic efficacy.
Clinical Management
The tremor from terbutaline is:
- Self-limiting and transient 1
- Does not typically require discontinuation 1
- Predictable and dose-related 1
- Can be minimized by using inhaled rather than parenteral routes when clinically appropriate 5
In overdose situations, tremor may be exaggerated along with other beta-adrenergic symptoms, and judicious use of cardioselective beta-blockers may be considered (though this risks bronchospasm). 1