What side effects can haloperidol have?
Below you will find the most important information about possible known side effects of Haloperidol.
These side effects do not occur, but you can. Because every person reacts differently to medication. Please also note that the type and frequency of side effects may vary depending on the drug formulation (eg tablet, syringe, ointment).
Common side effects at the start of therapy:
Fatigue, tongue cramps, pharyngeal cramps, head movement cramps, cervical spasms, shoulder movement spasms, torticollis, gaze spasms.
Common side effects after prolonged treatment:
Lack of exercise, muscle stiffness, tremor, restlessness, discomfort.
Uncommon side effects:
Lowering blood pressure, blood pressure regulation disorders, rapid heart rate, facial swelling, arm swelling, leg swelling, hair loss, erectile dysfunction, chronic erections, respiratory disorders, dyspnea, pneumonia.
Rare side effects:
restlessness, drowsiness, depressed mood, listlessness, dizziness, headache, delirium-like states with loss of reality, seizures, body temperature fluctuations, speech disorders, memory disorders, sleep disorders, nausea and vomiting, diarrhea, constipation, loss of appetite, heartburn , Gastric acid production disorders, transient hepatic elevation, allergic skin rashes, corneal cavities, eye lens retention.
At high dosage:
blurred vision, dry mouth, nasal congestion, urinary problems, intraocular pressure increase.
Very rare side effects and isolated cases:
Life-threatening neuroleptic syndrome (with sedentary lifestyle, high fever, impaired consciousness, coma, cardiac arrhythmia), circulatory failure, intestinal obstruction, cardiac conduction extension, cardiac arrhythmia, menstrual disorders, swelling of the mammary glands, sexual dysfunction, morbid milk flow, male breast growth, Blood sugar problems, urine flow increase, urine flow reduction, jaundice, bone thrombosis, pelvic vein thrombosis, white blood cell deficiency, red blood cell deficiency, platelet deficiency.
It seems that older patients, especially older women, are more susceptible to involuntary movement disorders than neuroleptic side effects (tardive dyskinesias). The risk of tardive dyskinesias and the fact that they do not improve any more, probably increases with the duration of treatment and the dosage of the drug. However, a late dyskinesia can develop even after a short period of treatment and at low dosage. Treatment with haloperidol itself may initially obscure the signs of onset tardive dyskinesia. After the end of the treatment, it will appear visibly.
Because haloperidol increases the convulsiveness of the brain, epilepsy patients should only be treated with the drug if they continue taking their antiepileptic drugs.
The function of the kidneys and the liver and the circulatory situation should be monitored by the doctor at regular intervals during therapy. Before starting the treatment, a blood count and a measurement of the stimulation conduction at the heart (ECG) as well as the brain waves (EEG) should be made in practice.
The risk of cardiac conduction disorder and the development of cardiac arrhythmia (torsades des pointes) is particularly high when the drug is given into the vein.
In case of high fever and muscle stiffness after taking haloperidol, think of a malignant neuroleptic syndrome and call the doctor immediately. Even with a low-grade fever, inflammation of the gums and mouth, sore throat or purulent angina and flu-like symptoms – especially if they occur within the first three months after starting treatment with haloperidol – the treating physician should be consulted immediately. p>
What interactions does Haloperidol show?
Please note that the interactions may vary depending on the drug formulation of a drug (eg tablet, syringe, ointment).
When alcohol or sedating medications are used concomitantly with haloperidol, the effects are mutually reinforcing. Therefore, alcohol should be avoided during the treatment.
During concomitant use of caffeine, haloperidol may be reduced in efficacy. Therefore, the use of caffeine (coffee, tea, caffeine-containing medicines) should be avoided during the treatment.
Haloperidol enhances the effects of most antihypertensive agents; the result may be a drop in blood pressure. Also, a drop in blood pressure is possible in combination with adrenaline. Increases in blood pressure due to the reduced effect of guarethidine and clonidine and the Parkinson’s drug levodopa occur when combining haloperidol with the antihypertensives. That is why regular blood pressure checks are required during such combined treatments.
The stimulant pentetrazole in combination with haloperidol may cause seizures. Patients combining both agents should be monitored with special care.
When combined with anticholinergics (a group of drugs that inhibit the body’s own messenger acetylcholine), these medications become more potent. This also increases the risk of side effects.
Increased risk of life-threatening cardiac arrhythmias, especially when haloperidol is added to the vein, when given concomitantly with medications that may affect heart stimulation or cause blood potassium depletion. Drugs in this group include class IA or III antiarrhythmics, macrolide antibiotics, H1 antihistamines, dehydrators, laxatives, and agents that can inhibit the breakdown of haloperidol, such as the acid blockers cimetidine and fluoxetine (for depression).
When co-administered with haloperidol and Parkinson’s agents such as bromocriptine and levodopa, as well as amantadine associated with the NMDA antagonists, their effects are attenuated. Dose adjustment by the attending physician may be necessary.
Concomitant use of prokinetics (a group of medicines used to treat nausea), such as metoclopramide, bromopride and alizapride, may lead to increased side effects such as muscle spasms and involuntary muscle twitching.
Medicines that induce liver breakdown, such as barbiturates (tranquilizers) and the anticonvulsant carbamazepine, accelerate the breakdown of haloperidol. Its effect is thereby reduced and a dose adjustment by the attending physician is necessary.
Furthermore, tricyclic antidepressants and lithium (used for depression) and the beta-blocker propranolol (antihypertensive agent) in combination with haloperidol lead to increased concentrations of these drugs in the blood. Therefore, increased side effects may occur.
When haloperidol is combined with the antiepileptic drug phenytoin, the concentration of phenytoin in the blood increases. Patients must be carefully monitored by a doctor. Dose adjustment may be required.