Paliperidone is an atypical neuroleptic. It has high neuroleptic potency.
What is paliperidone?
Paliperidone is classified in the group of atypical neuroleptics. It is used for schizophrenia. Paliperidone is categorized in the group of atypical neuroleptics. The drug is used in the EU under the preparation names Invega and Xepilon against schizophrenia. Paliperidone is the main active metabolite of the active ingredient risperidone. Paliperidone was approved for use throughout the European Union in 2007, with Switzerland joining in a year later. Austria, however, is an exception. The drug is not available there because its reimbursability was rejected by the Main Association of Austrian Social Insurance Institutions. In 2014, press reports of the deaths of 17 Japanese schizophrenia patients who had previously been injected with paliperidone caused a stir. However, there is no clarity as to whether the active ingredient played a role in the deaths of the patients. Moreover, its use has not been discouraged, so paliperidone is still on the market. In addition, there have also been no warnings from German or European regulatory agencies to date.
Pharmacologic effect
Because of their sedative and antipsychotic effects, neuroleptics are considered helpful against schizophrenia. Paliperidone belongs to the atypical neuroleptics and has the effect of inhibiting nerve messengers such as epinephrine, norepinephrine, dopamine, histamine, and serotonin in their mode of action. This is also the difference to other first-generation neuroleptics. The effect results from the binding of paliperidone to the corresponding receptors of the brain. In contrast, paliperidone cannot bind to the neurotransmitter acetylcholine. This has the advantage that there is less reduction of movements and less rigidity of limbs than with other neuroleptics. Similarly, there are fewer involuntary mouth and tongue movements caused by paliperidone as opposed to classical neuroleptics. The oral bioavailability of paliperidone is 28 percent. It is important for the absorption of the neuroleptic whether it is taken after a meal or on an empty stomach. Once the patient has decided on one of these two dosage forms, he or she should consistently stick with it. Paliperidone is primarily broken down by the kidneys. Depending on how well the patient’s kidney function is progressing, a reduction in dose may be necessary.
Medicinal use and application
Paliperidone is usually administered only for schizophrenia. However, since 2011, the drug has also been considered suitable for the treatment of manic and psychotic symptoms in schizoaffective disorder. Thus, paliperidone is the first neuroleptic in the European Union to be used against these symptoms. Paliperidone, on the other hand, was withdrawn for the treatment of acute manic episodes in the context of bipolar disorders. The reason for this was insufficient clinical evidence of the drug’s efficacy. Paliperidone can be administered either in tablet form or as an injection, which has a long-term effect. When administered by injection, psychotic symptoms should be mild to moderate. In addition, therapy with a depot antipsychotic must be necessary. Paliperidone tablets are taken once a day, always at the same time of day.
Risks and side effects
Just as with the use of other neuroleptics, undesirable side effects are possible with the use of paliperidone. However, these do not automatically manifest themselves in every patient. In most cases, affected individuals suffer from headaches and insomnia. Furthermore, sore throat, respiratory infections, nasal congestion, moodiness, joint pain, movement disorders, increase in blood sugar levels, involuntary movements, restlessness when sitting, drowsiness, dizziness, nausea, vomiting, high blood pressure, constipation, diarrhea, abdominal pain, palpitations, tremors, back pain, rashes on the skin, pain in the limbs, feelings of weakness, and toothache may occur. If paliperidone was administered as an injection, pain or induration sometimes appears at the injection site.If a patient develops symptoms of a malignant neuroleptic syndrome such as stiffening of the muscles, hyperthermia and disturbances of consciousness, the preparation must be discontinued immediately. The same applies to involuntary facial and tongue movements. There are also some contraindications to paliperidone. For example, the neuroleptic must not be administered if the patient suffers from hypersensitivity to the active substance or risperidone, which is related to paliperidone. It is also not advisable to use the drug in cases of severe renal dysfunction. The risk and benefit of paliperidone treatment must be carefully assessed by a physician in the case of cardiovascular diseases such as a heart attack, cardiac muscle weakness or low blood pressure, diabetes mellitus (diabetes), impaired liver function, epilepsy, venous blockages, Parkinson’s disease, and dementia. In pregnancy and lactation, paliperidone should be administered only when absolutely necessary. Thus, temporary nervous disturbances may occur in the infant. Administration of paliperidone in children and adolescents is not permitted, as there is no knowledge about the effect and side effects of the drug in them. When using paliperidone, attention must also be paid to interactions with other drugs. This applies in particular to drugs that alter the heart rhythm. These include, above all, antiarrhythmic drugs such as sotalol, disopyramide, amiodarone and quinidine. Also affected are various antipsychotics, H1 antihistamines, and antimalarials such as mefloquine. In addition, because paliperidone affects the brain, caution is advised with concomitant administration of brain-acting drugs such as opioid analgesics, sleeping pills, or alcohol. Paliperidone has an abrogating effect on levodopa and other drugs administered for Parkinson’s disease. The use of antihypertensive agents is also considered risky because paliperidone can cause an abrupt drop in blood pressure.
