Does Aripiprazole (Abilify) cause polydipsia or increased thirst?

Aripiprazole and Polydipsia: Relationship and Clinical Implications

Aripiprazole (Abilify) does not commonly cause polydipsia or increased thirst as a primary side effect, but it may indirectly lead to these symptoms through metabolic effects or syndrome of inappropriate antidiuretic hormone (SIADH) in rare cases.

Mechanism and Evidence

Aripiprazole is a unique antipsychotic with a distinct receptor binding profile that combines partial agonist activity at D2 and 5HT1A receptors with antagonism at 5HT2A receptors 1. Unlike many other antipsychotics, aripiprazole has generally been associated with fewer metabolic side effects.

When examining the evidence regarding polydipsia:

• The primary literature does not list polydipsia or increased thirst among the common side effects of aripiprazole 2
• Aripiprazole is considered to have a more favorable metabolic profile compared to other antipsychotics like olanzapine, clozapine, quetiapine, and risperidone 3
• While some antipsychotics are known to cause significant metabolic effects that might lead to polydipsia, aripiprazole is generally considered to have fewer such effects 1

Potential Mechanisms for Thirst in Rare Cases

Though uncommon, there are several potential mechanisms by which aripiprazole might indirectly lead to increased thirst:

1. SIADH (Syndrome of Inappropriate Antidiuretic Hormone): There is a documented case report of aripiprazole-induced SIADH 4. This rare adverse effect can lead to hyponatremia, which may present with symptoms including increased thirst.

2. Diabetic Complications: Though rare, there is a case report of diabetic ketoacidosis associated with aripiprazole 5. Hyperglycemia and diabetic states can cause polydipsia as a compensatory mechanism.

3. Dry Mouth: Aripiprazole can cause dry mouth as a side effect, which might be interpreted as or lead to increased thirst 2.

Monitoring Recommendations

If a patient on aripiprazole reports increased thirst:

• Monitor serum sodium levels to rule out hyponatremia and possible SIADH
• Check blood glucose levels to rule out hyperglycemia or diabetes
• Assess for other symptoms that might indicate metabolic disturbances
• Consider measuring aripiprazole serum levels, as therapeutic drug monitoring can be helpful in optimizing therapy and minimizing side effects 6

Clinical Management

If increased thirst or polydipsia occurs in a patient taking aripiprazole:

1. Evaluate severity and impact: Determine if the symptom is significantly affecting quality of life
2. Rule out other causes: Check for diabetes, kidney dysfunction, or other medications that might cause polydipsia
3. Consider dose adjustment: Therapeutic response with minimal side effects has been associated with aripiprazole serum levels between 150-300 ng/ml 6
4. Alternative options: If symptoms persist and are troublesome, consider switching to another antipsychotic with a different side effect profile

Conclusion

While aripiprazole is generally considered to have a favorable side effect profile compared to many other antipsychotics, clinicians should remain vigilant for rare adverse effects including those that might lead to increased thirst or polydipsia. The occurrence of such symptoms warrants further investigation to rule out serious metabolic complications.