Can Invanz (ertapenem) cause tremors?

Ertapenem (Invanz) Can Cause Tremors

Yes, ertapenem (Invanz) can cause tremors as part of its neurological side effect profile. The FDA drug label specifically warns about central nervous system adverse effects including focal tremors, myoclonus, and seizures 1.

Neurological Side Effects of Ertapenem

Ertapenem can cause several neurological adverse reactions:

• Tremors
• Myoclonus
• Seizures
• Encephalopathy
• Altered mental status
• Dysarthria
• Gait instability

These neurological side effects are documented in the FDA warnings and precautions section for ertapenem 1. The drug label specifically states that "If focal tremors, myoclonus, or seizures occur, patients should be evaluated neurologically" and may require anticonvulsant therapy and/or dose adjustment or discontinuation of ertapenem.

Risk Factors for Ertapenem-Induced Neurotoxicity

Several factors increase the risk of developing neurological side effects with ertapenem:

• Pre-existing CNS disorders: Patients with brain lesions or history of seizures 1
• Renal impairment: Higher blood concentrations of ertapenem are associated with increased neurotoxicity risk 2
• Moderate renal insufficiency: 9.2 times higher odds of neurological complications 2
• History of previous neurologic disease: 9.9 times higher odds of neurological complications 2
• Elevated blood concentrations: Mean trough ertapenem blood concentration was significantly higher in patients experiencing neurotoxicity (37.8 mcg/mL vs 14.6 mcg/mL) 2

Time Course and Management

Neurological symptoms from ertapenem typically:

• May begin after several days of therapy (often around day 7) 3
• Can include vocal tremors 4
• Usually resolve within 24-48 hours after discontinuation of the medication 5, 3

If tremors or other neurological symptoms develop:

1. Evaluate the patient neurologically
2. Consider discontinuation of ertapenem
3. Consider alternative antibiotics if continued antimicrobial therapy is needed
4. If ertapenem must be continued, consider anticonvulsant therapy and/or dose adjustment

Clinical Implications

The development of tremors in a patient receiving ertapenem should prompt immediate evaluation. Case reports document dramatic improvement in neurological symptoms, including tremors, within 24 hours of discontinuing ertapenem 5. This rapid resolution after discontinuation strongly supports ertapenem as the causative agent.

For patients who have experienced ertapenem-induced neurotoxicity but require carbapenem therapy for severe infections, meropenem may be considered as an alternative with potentially lower neurotoxicity risk 5, though this should be approached with caution, especially in patients with renal impairment.