Rechallenging Clozapine After Neuroleptic Malignant Syndrome

Neuroleptic malignant syndrome (NMS) is a potentially fatal manifestation of antipsychotic use associated with symptoms that include mental status changes, muscle rigidity, fever and autonomic dysfunction. An occurrence of NMS with clozapine has been reported in the past but there are very few reports of successfully rechallenging the drug in individuals who have developed the syndrome. This case report discusses one of the few instances in literature where clozapine has been re-administered successfully to a patient without a reoccurrence of NMS. In conclusion, a rechallenge of clozapine after neuroleptic malignant syndrome can be done if care is taken to avoid concurrent use of lithium and other psychotropics, monitoring for NMS symptoms and titrating the dose upward slowly after a reasonable period of time.     

Clozapine and jaw dyskinesia: a case report.

No convincing case of tardive dyskinesia has been associated with clozapine. We briefly discuss a case of clozapine-induced reversible initial dyskinesia described in the German literature, and we report a case of jaw dyskinesia in a 49-year-old female schizophrenic. The dyskinesia appeared 2 weeks after the patient started clozapine treatment, did not respond to anticholinergic medication, and has continued for more than 1 year while the patient has remained on clozapine treatment. The patient had taken haloperidol (less than or equal to 5 mg/day) for 5 weeks before starting clozapine treatment. These are the only two cases of dyskinesia associated with clozapine use that are known to us. They raise the possibility that clozapine can induce dyskinesia.     

Serious respiratory infections can increase clozapine levels and contribute to side effects: a case report

Clozapine is mainly metabolized by the cytochrome P450 1A2 (CYP1A2), which may be inhibited by serious respiratory infections. This case report supports that a serious respiratory infection may increase clozapine levels and contribute to side effects. Plasma clozapine and norclozapine levels were monitored 17 times during 1 year. The concentration-to-dose ratio (C/D), an index of metabolic activity, was obtained by dividing the sum of plasma clozapine and norclozapine concentration (total clozapine concentration) by clozapine dose. The coefficient of variation (CV) of the total clozapine concentrations was calculated at different doses to provide a measure of the noise associated with determining clozapine concentrations in clinical practice. During a respiratory infection, the patient was taking 600 mg/day of clozapine. Clozapine levels were 1245 ng/ml (norclozapine 472 ng/ml), reflecting a decrease in clozapine metabolism by approximately a factor of 2. The high clozapine levels were associated with side effects (myoclonus and increased sedation). The C/D during the infection was 2.9, while the rest of C/Ds ranged between 1.0 and 1.6. CVs before and after the infection, at different doses, were always lower than 20%. When the level during the infection was included to calculate the CV on 600 mg/day, the CV increased to 54%. The theophylline literature, a prior case report and this case all suggest that if a clozapine patient develops a severe respiratory infection with fever, the psychiatrist must pay particular attention to any signs suggestive of major clozapine toxicity associated to a decrease in clozapine metabolism. If any of these signs appear, the psychiatrist may need to consider cutting the clozapine dose in half until the patient has recovered from the infection.     

Combination of clozapine and amisulpride in treatment-resistant schizophrenia--case reports and review of the literature

BACKGROUND: The clinical outcome of patients suffering from schizophrenic psychoses has been considerably improved by atypical antipsychotics like clozapine and amisulpride. In patients whose symptomatology cannot be ameliorated by monotherapy, it might be necessary to combine two atypical antipsychotics. While clozapine interacts with a variety of neurotransmitter receptors, amisulpride predominantly binds with high affinity to D3/D2-dopamine receptors. Combination can be considered if a supplementary dopamine-receptor blockade is desired. METHODS: We report on the therapy of 15 patients using a combination regimen of amisulpride and clozapine. Data were collected from patient records. The case reports document previous treatment attempts, describe the reason for the combination therapy, and determine its effect. RESULTS: Major (six cases) or at least marked (eight cases) improvement of previously treatment-resistant positive and negative symptoms could be achieved by using a mean clozapine dose of 375 mg/day (serum level 0.38 mg/l) and an amisulpride dose of 527 mg/day. Additionally, by reducing the clozapine dose compared to monotherapy by 24 %, a significant reduction of side effects was observed. CONCLUSIONS: The combination of amisulpride with clozapine considerably enriches the therapeutic arsenal in cases of severe schizophrenic psychoses. Additional prospective studies are needed in order to systematically evaluate this new treatment strategy.     

Successful switch to olanzapine after rhabdomyolysis caused by water intoxication and clozapine use

We report on a case of rhabdomyolysis induced by the correction of hyponatremia after psychogenic polydipsia and clozapine use, where the switch to a high dose of olanzapine resulted in the non-recurrence of rhabdomyolysis. The 46-year-old patient with the diagnosis of schizophrenia paranoid type, who had been on clozapine treatment for the previous 4 years, was admitted with the symptoms of generalized seizure and vomiting, and as severe hyponatremia was proved, its correction with the parallel use of clozapine treatment was done. CK concentrations increased to 48 120 U/L without any symptom of neuroleptic malignant syndrome. To prevent acute renal insufficiency, high-volume alkaline diuresis was initiated and clozapine was tapered and stopped. On the day 12 of treatment, olanzapine was started and was elevated to 30 mg/day. CK concentration began to fall returning to the normal concentration on day 20. Six months after the switch to olanzapine no recurrence of rhabdomyolysis was detected; clinical and laboratory findings were normal. We suggest that after a benzodiazepine-type antipychotic-induced rhabdomyolysis, a switch to another atypical antipsychotic can be a cautious clinical strategy.     

Clozapine and pregnancy

This article reviews the relations between clozapine and pregnancy. Six case reports are identified in the literature of pregnant patients who received clozapine. Novartis at Basle, Switzerland, through its pharmacovigilance and epidemiology, service, has data on nearly 200 cases summarized in this article. We also describe the case of a patient with paranoid schizophrenia who was hospitalized 10 times between the age of 22 to 32. She received clozapine when she was 29 years old and, with a daily dosage of 350 mg, she became asymptomatic. At the age of 33 and 37, she became pregnant and continued clozapine during her 2 pregnancies. During her first pregnancy, she received insulin due to gestational diabetes associated with a body weight mass (BWM) of 30.4 (N = 20 to 25). During her second pregnancy, the BWM was 23.7 and she did not develop diabetes. She delivered at term 2 daughters who are at the time of this report 5 and 3 years old. The two girls are doing well and have no developmental delay. Psychotic symptoms exacerbation: the plasma concentration of clozapine diminishes during pregnancy due to a higher hepatic metabolism and distribution volume. Monitoring plasma concentration of clozapine can help to adjust its dosage. In case of psychotic symptoms exacerbation, the following can be recommended: 1) Increase the clozapine dosage; 2) Add a classic antipsychotic like perphenazine, trifluoperazine or haloperidol. Diabetes: obesity, glucose intolerance or a family history of diabetes are risk factors to develop gestational diabetes. The follow-up of patients, who take an atypical antipsychotic, should include constant monitoring of the blood glucose or Hb1A and lipid dosages. Complications at labor: Clozapine increases the secretion of oxytocine and the contraction of the uterine muscle. But, no studies can explain how clozapine affects the labor exactly. Some case studies report use of forceps, vacuum or cesarean. CONVULSIONS: Stoner (1997) described neonatal convulsions 8 days after birth. The mother was receiving 350 mg of clozapine, but also lorazepam and haloperidol during her pregnancy. The newborn withdrawal of lorazepam can increase the risk of convulsions and also haloperidol can diminish the convulsion threshold. Floppy infant syndrome: in the case described by Dimichele (1996), the mother received a daily dosage of 300 mg of clozapine and 2.5 mg of lorazepam 3 to 5 times a day. This can explain hypotonia. Stoner (1997) reports a second case where a mother, who received 600 mg of clozapine during pregnancy, gave birth to a child who had no convulsions neither hypotonia. DEVELOPMENT: The cases described concerning studies of children until age 2 to 3 years by Stoner (1997) and Dickson (1998) and until 6 years old by Barnas (1994), do not mention any developmental problem, similar to the two daughters of our patient. The pharmacovigilance service of Novarits reports 6% of malformations. But these reports must be considered with caution since they represent only the pregnancies reported spontaneously to the pharmaceutical company. This is only a portion of all pregnancies associated with clozapine. CONCLUSION: No specific risks for the mother and children can be attributed to the use of clozapine during pregnancy. However, the plasma concentration of clozapine is higher in the fetus compared to the mother (Barnas, 1994); therefore, a minimal dosage should be used. Since clozapine is present in the maternal milk, breast feeding should be avoided. The advantages to use clozapine during pregnancy must exceed the risks. It is justified to continue the use of this medication even if data on classic antipsychotics (e.g.: haloperidol) are more extensive. Because the risk of psychotic exacerbation is higher, the substitution of clozapine is not recommended. The psychosocial support and the obstetrical follow-up must be intensive too. An institutional pharmacovigilance service should complement the one provided by the industry. Also, further case-control and cohort studies are essential to better estimate the long-term risks.     

Amisulpride related tic-like symptoms in an adolescent schizophrenic

Tic disorders can be effectively treated by atypical antipsychotics such as risperidone, olanzapine and ziprasidone. However, there are two case reports that show tic-like symptoms, including motor and phonic variants, occurring during treatment with quetiapine or clozapine. We present a 15-year-old girl schizophrenic who developed frequent involuntary eye-blinking movements after 5 months of amisulpride treatment (1000 mg per day). The tic-like symptoms resolved completely after we reduced the dose of amisulpride down to 800 mg per day. However, her psychosis recurred after the dose reduction. We then placed her on an additional 100 mg per day of quetiapine. She has been in complete remission under the combined medications for more than one year and maintains a fair role function. No more tic-like symptoms or other side effects have been reported. Together with previously reported cases, our patient suggests that tic-like symptoms might occur in certain vulnerable individuals during treatment with atypical antipsychotics such as quetiapine, clozapine, or amisulpride.     

Global availability of clozapine and the risk of decompensation for recent geriatric patients from Africa: A case report

In individuals with schizophrenia resistant to other antipsychotics, the atypical antipsychotic, clozapine, has been found to be an effective treatment. However, the associated risk of agranulocytosis, routine testing and monitoring of the absolute neutrophil count (ANC) is required. We report a case of a chronically ill 70-year-old woman who migrated from Africa and had been successfully treated with clozapine while in her home country and then in the United States. A testament to the increased availability of state of the art treatment globally and challenges of migration in geriatric patients. She presented to the hospital, due to agitated behavior and noncompliance with medications. She had been on clozapine 150 mg daily for the past 4 years. In the past, she had tried several antipsychotics for multiple psychotic episodes but reported a poor response. Prior to moving to the United States about 9 months ago, she had been compliant with clozapine 150?mg/day, and also had an extensive history of outpatient and inpatient treatment in her home country. The patient decompensated due to medication noncompliance. This case explores patient outcome if clozapine treatment is abruptly discontinued and subsequently reinstated with other antipsychotic medications as well as the factor of migration as a significant stressful event in the etiology of psychiatric disorders. Migrating to a new country can be challenging, especially for geriatric patients given acculturation challenges which may result in medication noncompliance. We recommend that geriatric patients be closely monitored during migration to minimize decompensation risks.     

The influence of N-desmethylclozapine and clozapine on recognition memory and BDNF expression in hippocampus

Clozapine, which is the most effective treatment option for treatment-refractory schizophrenia, has been reported to have both positive and negative effects on specific cognitive symptoms in patients with schizophrenia and in animal models of cognition. Clozapine has a major metabolite, N-desmethylclozapine (NDMC), which has been suggested to be more effective than clozapine itself to improve cognition. Enhancement of brain derived neurotrophic factor (BDNF) expression in the hippocampus has been proposed to contribute to the cognitive-enhancing effects of antipsychotic drugs. The aims of this study were to investigate the change in short and long term memory as assessed by the novel object recognition (NOR) test and BDNF expression in hippocampus produced by an acute hypoglutamatergic model of memory impairment in schizophrenia induced by administration of the NMDA receptor non-competitive antagonist, MK-801 and the ability of clozapine and NDMC to prevent the deleterious effects of MK-801. Both short (1 h) and long-term (24 h) memory were impaired in MK-801 (0.1 mg/kg) - and clozapine (5 mg/kg)-, but not NDMC (5 mg/kg)-treated rats. Neither NDMC (5 mg/kg) nor clozapine (5 mg/kg) reversed the effect of MK-801. Western blotting studies showed that BDNF levels in hippocampus were not different in rats administered MK-801 alone, clozapine or NDMC alone. These results show that in this model clozapine affects memory negatively, while NDMC does not. The absence of impairment of NOR with NDMC is consistent with previous evidence that it has a more benign effect on cognition than does the parent compound, and may support the efforts to study its effects on other cognitive functions. These findings do not provide any support for the role of BDNF in the MK-801-induced impairment in NOR or for differences between clozapine and NDMC.     

Reversible Pisa syndrome induced by clozapine: a case report

Pisa syndrome, manifested with persistent lateral flexion of the trunk, is most commonly associated with prolonged treatment with typical antipsychotics. However, it was also reported as occurring with atypical antipsychotics. To our knowledge, there have been very few reports of clozapine-associated Pisa syndrome. Here we report 1 case of Pisa syndrome in a 39-year-old woman with schizoaffective disorder who developed tonic flexion of trunk and head toward the left side after clozapine treatment (400 mg/d) for 5 months. Clozapine was reduced to 25 mg/d within 15 days; the dystonic reaction then completely resolved within the next 3 to 4 weeks. Caution should be taken while prolonged use of clozapine in patients with risk factors of Pisa syndrome.     

Clozapine for blepharospasm, obsessive-compulsive symptoms, and psychotic symptoms in a patient of old brain infarction

Blepharospasm, psychotic symptoms, and obsessive-compulsive symptoms can result from brain infarction. However, a presentation of these 3 symptoms simultaneously is rare. This report describes a 65-year-old woman who had old brain infarction and presented with these 3 symptoms for 2 years. The patient recovered after receiving a regimen of clozapine 125 mg/d for 3 months. No recurrences of symptoms were noted during a 6-month follow-up. This is the first case report demonstrating that clozapine is effective for a patient with blepharospasm, obsessive-compulsive symptoms, and psychotic symptoms presenting simultaneously. This report also reminds physicians of the possible organic causes of unusual presentations in elderly patients.     

Neuroleptic-induced catatonia or a mild form of neuroleptic malignant syndrome?

Neuroleptic-induced catatonia (NIC) and milder neuroleptic malignant syndrome (NMS) share parkinsonian features, catatonic symptoms, mild fever, and have been described in patients receiving antipsychotic agents. We report the case of a patient with a schizophreniform disorder and a mild mental retardation who developed a condition which can be diagnosed either as NIC or as a mild form of NMS and has been treated successfully with a combination of amantadine (600 mg/day) and diazepam (30 mg/day). The overlapping between NIC and mild NMS cases might lead to an overestimation of the incidence of current NMS and reinforces the view of the existence of a 'neuroleptic toxicity spectrum'.     

Clozapine treatment in oromandibular dystonia

Oromandibular dystonia (OMD) is a form of focal dystonias, which can be associated with substantial disability and is frequently refractory to all antidystonic therapies. Clozapine is a dibenzodiazepin derivative atypical neuroleptic that has been reported to be effective in the treatment of primary or symptomatic dystonia. We report here two patients with severe OMD refractory to other antidystonic therapies, who had substantial improvement with clozapine. We suggest that clozapine should be considered in patients with OMD who fail to response to other treatments.     

Obsessive compulsive symptoms in patients with Schizophrenia on Clozapine and with Obsessive Compulsive disorder: A comparison study

Obsessive compulsive symptoms are commonly reported in those with schizophrenia. Clozapine has previously been reported to induce, aggravate and alleviate these symptoms. It is unclear if these are similar to the symptoms experienced by those with obsessive compulsive disorder. This study describes the obsessive compulsive symptom profile of a population of patients with schizophrenia treated with clozapine (n = 62) and compares this with patients with Obsessive Compulsive Disorder (n = 35). All participants were attending an outpatient community mental health service. The Obsessive Compulsive Inventory (which measures the frequency and associated distress of a range of “behavioural” and “cognitive” symptoms), the Hospital Anxiety and Depression Scale and a demographic questionnaire were completed. In addition the schizophrenia group treated with clozapine completed the Brief Psychiatric Rating Scale. The OCD group reported significantly more symptoms for all OCI subscales compared to the clozapine group. Overall fourteen (22%) of the schizophrenia treated with clozapine group had clinically significant total OCI scores. Two (3%) had documented OCS pre clozapine. De novo OCS was reported in twelve (19%) cases. Nine (11%) had documented OC symptoms pre-clozapine while only two (3%) had symptoms after clozapine was initiated. In terms of OC symptom profile, the clozapine group scored highest on the Doubting scale, a cognitive symptom whereas the OCD group scored highest on Washing, a behavioural symptom. Both groups reported greater distress with cognitive rather than behavioural symptoms. Medication including clozapine dose was not correlated with symptom severity. Anxiety correlated highly with obsessive compulsive symptoms in the Clozapine group but not the OCD group. Within the Clozapine group, Obsessing correlated highly with Unusual Thought Content. Findings suggest that obsessive compulsive symptoms in the Clozapine group may reflect a subtype of 'schizo-obsessive' disorder.     

Differential alterations in striatal acetylcholine function in rats during 12 months' continuous administration of haloperidol, sulpiride, or clozapine

Rats were treated continuously for 12 months with therapeutically equivalent doses of either haloperidol (1.4-1.6 mg/kg/day), sulpiride (102-109 mg/kg/day), or clozapine (24-27 mg/kg/day). After treatment for 3 and 12 months with haloperidol or clozapine but not sulpiride, striatal acetylcholine levels were increased. Striatal choline acetyltransferase activity was not altered by any drug treatment. Vmax for striatal acetylcholinesterase activity during the course of 12 months' treatment with haloperidol or clozapine, but not with sulpiride, tended to increase; Km was not altered by any drug treatment. Bmax for specific striatal [3H]quinuclidinyl benzilate binding was not altered by haloperidol or sulpiride treatment but was transiently elevated after 6 months of clozapine treatment, thereafter returning to control levels. Kd was not altered by any drug treatment. These findings indicate that alterations in striatal acetylcholine content caused by chronic treatment with some but not all neuroleptics are due to changes in cholinergic neuronal activity rather than neurotransmitter synthesis or destruction. The effects of haloperidol but not those of clozapine may be related to the emergence of functional striatal dopamine receptor supersensitivity. Since haloperidol (which is associated with a high prevalence of tardive dyskinesias) but not clozapine (which is not) had similar effects on striatal cholinergic function, the latter may not be related to the emergence of tardive dyskinesias during chronic therapy.     

Effects of clozapine and olanzapine on cytokine systems are closely linked to weight gain and drug-induced fever

The second generation antipsychotics clozapine and olanzapine are known to cause weight gain. However, only clozapine is associated with drug-induced fever. Cytokines have been linked to the induction of both weight gain and drug-induced fever. We investigated these potential side effects of clozapine and olanzapine and studied their differential effects on cytokine secretion. Thirty patients suffering from schizophrenia, schizophreniform disorder or schizoaffective disorder were treated with either clozapine (mean modal dose: 266.7+/-77.9mg) or olanzapine (21.2+/-2.5mg) in a randomized, double-blind, 6-week study. Body mass index (BMI), tympanic temperature, and plasma levels of leptin and cytokines (tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptor 1 and 2 (sTNFR-1/2), soluble interleukin-2 receptors (sIL-2R), interleukin-6) were determined weekly. BMI, leptin and cytokines significantly increased over time, except interleukin-6 and sTNFR-1 in the olanzapine group. All cytokines numerically increased compared to baseline already during the first week of treatment in both groups. Leptin, TNF-alpha, sTNFR-1, sTNFR-2 and sIL-2R levels correlated with the BMI. Five patients who received clozapine (33%) developed drug-induced fever (>/=38 degrees C). In these, interleukin-6 peak levels were significantly (p<0.01) higher than in those patients treated with clozapine who did not develop fever. In conclusion, increase of BMI appears to be related to clozapine's and olanzapine's similar effects on cytokine systems, whilst drug-induced fever appears to be related to clozapine's differential effects on interleukin-6.     

Clozapine-induced seizures: recognition and treatment.

OBJECTIVES: To inform clinicians about the types of seizures that can be induced by clozapine and to provide recommendations for treatment. METHODS: We identified articles on clozapine-induced seizures from a MEDLINE search of the English-language literature from 1978 to July 2006. The frequency of each type of seizure and the dosages of clozapine associated with seizures were compiled. In addition to this review, we report a new case illustrating the challenge of diagnosing subtle seizure activity. RESULTS: The tonic-clonic variety is the most frequently described clozapine-induced seizure. Myoclonic and atonic seizures together constitute about one-quarter of the reported seizures. The mean dosage of clozapine associated with seizures is not high (less than 600 mg daily). CONCLUSIONS: It may be difficult for clinicians to recognize subtle types of clozapine-induced seizures, such as myoclonic, atonic, or partial seizures. Clinicians should not place excessive reliance on the plasma level of clozapine or electroencephalogram findings to predict the occurrence of seizures. When a first seizure occurs, it is recommended that the dosage of clozapine be reduced or an alternative antipsychotic agent be employed. If a second seizure occurs, an anticonvulsant drug should be started. Special attention should be paid when commencing or discontinuing concurrent medication that may affect the plasma level of clozapine.     

Myotoxicity in acute clozapine overdose

Clozapine, an atypical antipsychotic has been associated with several side effects like sialorrhoea, sedation, tachycardia, agranulocytosis and seizure. Myotoxicity and neurotoxicity have also been reported with long-term use of clozapine. We report here a case of myotoxicity developing after acute overdose of clozapine. A 17-year-old daughter of a schizophrenic father consumed 3.9 g of clozapine in an attempted suicide. Clinical features of myotoxicity were detected on the third day, after the patient regained full consciousness. Elevated creatinine phosphokinase and muscle biopsy confirmed myositis. The patient also had tachycardia, which persisted for 10 days. This combination of myositis-induced muscle weakness and tachycardia is likely to be associated with poor outcome in clozapine overdose.     

Clozapine treatment attenuated somatic and affective signs of nicotine and amphetamine withdrawal in subsets of rats exhibiting hyposensitivity to the initial effects of clozapine.

BACKGROUND: Based on the phenomenologic similarity between symptoms of drug withdrawal and the negative symptoms of schizophrenia (e.g., anhedonia), we hypothesized that treatment with clozapine may be effective against nicotine and amphetamine withdrawal. METHODS: A rate-independent discrete-trial threshold procedure was used to assess brain stimulation reward in rats prepared with electrodes in the lateral hypothalamus. Somatic signs of nicotine withdrawal were also assessed. RESULTS: Clozapine administration (.75 or 1.5 mg/kg) during nicotine or amphetamine withdrawal did not affect the threshold elevations associated with drug withdrawal. The.75 mg/kg clozapine dose reversed the increased number of somatic signs of nicotine withdrawal. Ten days of clozapine treatment (3 mg/kg/b.i.d.) before exposure to nicotine prevented the threshold elevations in a subset of rats and the increases in somatic signs in all subjects. Fourteen-day pretreatment with clozapine (6 mg/kg/day) decreased the duration of amphetamine withdrawal. CONCLUSIONS: Correlational analyses indicated that the ability of clozapine to prevent the affective aspects of drug withdrawal depended on low sensitivity to acute clozapine under baseline conditions. The results are consistent with the clinical situation where clozapine is partially effective against the negative symptoms of schizophrenia and more effective in some individuals than others. These results indicate that lack of sensitivity to the initial negative effects of clozapine may predict its a subsequent therapeutic response. Finally, the data suggest that there may be commonalities in the neurosubstrates mediating affective aspects of drug withdrawal and the negative symptoms of schizophrenia.