Bipolar disorder is a chronic condition characterized by significant shifts in mood, energy, and activity levels. Long-term treatment is necessary to stabilize mood episodes and prevent relapse, often involving daily oral medication. Maintaining this daily regimen is challenging for many individuals, leading to interest in alternative methods. Long-acting injectable (LAI) medications offer a practical option to ensure consistent, reliable treatment delivery over extended periods.
Current Status of Long-Acting Injectables for Bipolar
The monthly shot option for bipolar disorder is found within a class of treatments called long-acting injectable atypical antipsychotics. Two specific medications are FDA-approved for the maintenance treatment of Bipolar I Disorder. Risperidone is typically administered as an intramuscular injection every two weeks. Aripiprazole monohydrate is dosed once every four weeks, making it a true monthly shot option for maintenance therapy.
Beyond these options, other LAIs offer longer dosing intervals. Aripiprazole lauroxil can be administered every four, six, or eight weeks, and a newer extended-release formulation is given once every two months. Paliperidone palmitate is available in monthly, three-month, and six-month injectable formulations. While primarily FDA-approved for schizophrenia, these are often used off-label for bipolar disorder. Olanzapine pamoate is dosed every two to four weeks, but its use is often considered off-label and is limited by a mandatory post-injection observation period.
Why Injections Are Used for Mood Stabilization
The clinical rationale for using LAIs centers on improving medication adherence, a significant obstacle in managing chronic conditions. Non-adherence to daily oral medication is often high, increasing the risk of relapse and rehospitalization. Shifting administration responsibility to a healthcare provider virtually eliminates the likelihood of missing a dose. This offers a reliable strategy for long-term symptom management.
LAIs also provide a pharmacokinetic advantage by maintaining consistent therapeutic drug levels in the bloodstream. Unlike daily oral pills, which cause peaks and troughs, the long-acting depot releases medication slowly and steadily over weeks or months. This consistent level helps prevent fluctuations that might trigger a mood episode. LAIs serve as a powerful tool for relapse prevention, a primary goal of maintenance treatment.
Practical Considerations for Injectable Medication
Starting a long-acting injectable regimen involves several practical steps. Prior to beginning a LAI, the patient must first establish tolerance to the corresponding oral form of the medication. This confirms the patient can handle the drug’s effects and helps determine the correct dose. Many LAIs require an initial overlap period where the patient continues to take the oral medication for a couple of weeks after the first injection.
The injection is typically administered by a healthcare professional into a large muscle, such as the gluteal or deltoid muscle, in a clinic setting. Patients must be aware of potential side effects associated with the medication class, including metabolic changes like weight gain or alterations in blood sugar and lipid levels. Specific LAIs, such as olanzapine pamoate, require patients to be monitored for three hours after each injection. This monitoring addresses the rare risk of a post-injection syndrome involving sedation or delirium.