Can Quetiapine (quetiapine) cause heat sensitivity?

Quetiapine and Heat Sensitivity: Mechanism and Clinical Implications

Yes, quetiapine can cause heat sensitivity and increase the risk of heat-related illnesses due to its effects on thermoregulation. This side effect requires careful consideration, especially during hot weather or when patients engage in strenuous activities.

Mechanism of Quetiapine-Induced Heat Sensitivity

Quetiapine affects thermoregulation through several mechanisms:

1. Anticholinergic effects: Norquetiapine, an active metabolite of quetiapine, has moderate to strong affinity for muscarinic receptor subtypes 1. This anticholinergic activity can inhibit sweating, reducing the body's ability to dissipate heat.

2. Central thermoregulatory effects: Quetiapine, as an antipsychotic medication, affects dopamine receptors which can disrupt the body's central temperature regulatory centers 1.

3. Disruption of body temperature regulation: The FDA label specifically warns that quetiapine can disrupt the body's ability to reduce core body temperature 1.

Clinical Evidence and Case Reports

There is documented evidence of quetiapine contributing to heat-related illnesses:

• A case report described a fatal exertional heat stroke in a 36-year-old male who was taking quetiapine along with zuclopenthixol and benztropine while working as a roofer during a heat wave 2. The patient developed severe hyperthermia (42.2°C) and multiple organ dysfunction.

• Another case report documented recurrent heat-related illnesses in a patient taking multiple antipsychotics with anticholinergic properties 3. This demonstrates the potential for repeated episodes in susceptible individuals.

Risk Factors and Vulnerable Populations

Certain factors increase the risk of quetiapine-induced heat sensitivity:

• Combination with other medications: Risk increases when quetiapine is combined with other drugs that have anticholinergic properties 1.

• Environmental conditions: Hot weather, high humidity, and strenuous physical activity significantly increase risk 2.

• Elderly patients: They are more vulnerable to heat-related adverse effects and should use lower doses due to increased sensitivity to side effects 4.

• Dehydration: Can exacerbate the risk of heat-related illnesses in patients taking quetiapine 1.

Prevention and Management

To prevent heat-related illnesses in patients taking quetiapine:

1. Patient education: Inform patients about the risk of heat sensitivity and the importance of avoiding overheating.

2. Environmental precautions: Advise patients to stay in cool places during hot weather and avoid excessive sun exposure 1.

3. Hydration: Encourage adequate fluid intake, especially during hot weather 1.

4. Activity modification: Caution against over-exercising or strenuous physical activity in hot conditions 1.

5. Clothing considerations: Advise against wearing too much or heavy clothing in hot weather 1.

6. Monitoring: Patients should be aware of early signs of heat-related illness, such as dizziness, weakness, and confusion.

Clinical Pearls

• Heat sensitivity may not be immediately apparent when starting quetiapine but can manifest during seasonal temperature changes or with changes in activity level.

• The sedative effects of quetiapine may mask early warning signs of heat-related illness 1.

• Patients with comorbid medical conditions (especially cardiovascular disease) may be at higher risk for complications from heat sensitivity.

• Consider temporary dose reduction during extreme heat waves for high-risk patients.

• Heat-related symptoms should be treated as a medical emergency if severe, as they can rapidly progress to life-threatening heat stroke.

In conclusion, healthcare providers should be vigilant about the potential for quetiapine to cause heat sensitivity and should counsel patients appropriately, especially during hot weather seasons or when patients plan activities that might increase their core body temperature.