Seroquel can be helpful and effective, but it is also important to be aware of the potential side effects. This includes common symptoms such as constipation, drowsiness, and rapid heartbeat, as well as more serious side effects such as tardive dyskinesia.
Common Side Effects
Along with its therapeutic effects, Seroquel can sometimes cause side effects. Some side effects will have symptoms that you can see or feel. Your doctor may watch for others, such as changes in the lenses of the eyes, by doing certain tests. Check with your doctor if any of the following common side effects don’t go away or are bothersome:
Abdominal painAbnormal visionConstipationDecrease in appetiteDecreased strength and energyDizzinessDrowsinessDry mouthFast or irregular heartbeatHeadacheIncreased muscle toneIncreased sweatingIndigestionLightheadedness, or fainting, especially when getting up from a lying or sitting positionStuffy or runny nose
Serious Side Effects
In some cases, more serious side effects may occur. Some of these include:
Increased risk of death due to dementia-related psychosisIncreased risk of suicidal thoughtsPotential serious weight loss or weight gain
Seroquel can increase the amount of a hormone called prolactin. In some cases, this may interrupt menstruation or breastfeeding. It can also cause decreased sex drive and erectile dysfunction. Long-term exposure to elevated prolactin levels can increase the risk for osteoperosis and bone fractures.
Tardive Dyskinesia
Tardive dyskinesia, a movement disorder, may occur and may not go away after you stop using Seroquel. This was much more common with the older antipsychotic medications, but can very rarely occur with the newer atypical agents such as Seroquel. Signs of tardive dyskinesia include:
Chewing or sucking movementsGrimacing (making faces)Lip-smackingPuckering or pursing the lipsRapid eye blinkingTongue protrusionWorm-like tongue movements
Medication Interactions
Combining Seroquel with other medications can affect how each medication functions or may lead to increased or decreased side effects. Some of the medications that may interact with Seroquel include:
Anticonvulsants including carbamazepineAntidepressants including fluoxetineAntifungal drugs including itraconazole and ketoconazoleAntihistamines such as chlorpheniramine, diphenhydramine, or brompheniramineBarbiturates including phenobarbitalBenzodiazepines including alazopram, clonazepam, diazapam, and lorazepamHerbal supplements such as St. John’s wortHIV medications including indinavir and ritonavirMuscle relaxants including baclofen and metaxaloneParkinson’s medications including levodopaPain medications including codeine, hydrocodone, morphine, and oxycodone
Seroquel should not be taken with anti-arrhythmic drugs, pentamidine, or methadone. These medications may lead to potentially fatal heart rhythm problems if they are combined with Seroquel. For this reason, it is important to talk to your prescribing physician about other medications or supplements you are currently taking it. This medication can also lead to increased risks when combined with alcohol or illicit substance, so be sure to talk about any substances you might be using.
When to Seek Help
Another serious but extremely rare side effect that may occur as a result of taking Seroquel is neuroleptic malignant syndrome (NMS). Stop taking this medicine and get emergency help immediately if the following symptoms of NMS occur, particularly if they occur together:
Convulsions (seizures)Difficult or unusually fast breathingFast heartbeat or irregular pulseHigh feverHigh or low (irregular) blood pressureIncreased sweatingSevere muscle stiffness
Other Precautions
If you’re taking or plan to take Seroquel, keep in mind these precautions:
The FDA issued a black box warning on all antipsychotic drugs, including Seroquel, due to the increased risk of death in elderly patients with dementia-related psychosis. Because Seroquel may cause drowsiness, don’t drive or operate machinery until you know how it affects you. If you are pregnant or plan to become pregnant or if you are breastfeeding, tell your doctor. Don’t ever stop Seroquel or change the amount you are taking without your doctor’s approval, even if you feel better. This can lead to unwanted effects and problems managing your illness. Make sure you don’t miss any doses of Seroquel as this can lead to a relapse of the symptoms of your mental disorder. If you use alcohol or illegal drugs, tell your doctor since these may make any side effects you experience even worse. Make sure to drink plenty of fluids while on Seroquel and avoid becoming overheated.
