Sodium Benzoate Helps Treat Schizophrenia When Added to Clozapine
In a 2017 article in the journal Biological Psychiatry, Chieh-Hsin Lin and colleagues reported that sodium benzoate, a common food preservative, may augment the effects of clozapine in patients with schizophrenia.
Clozapine is the most effective antipsychotic available, but as many as 40–70% of patients with treatment-resistant schizophrenia do not respond to it. For those with a poor response to clozapine, sodium benzoate may offer some hope.
In a randomized, double-blind trial, sixty inpatients taking clozapine for schizophrenia were divided into three groups. One group received an additional 1 g/day of sodium benzoate, another received 2 g/day, and the third received placebo in addition to clozapine. Both groups taking sodium benzoate and clozapine showed improvements in negative symptoms of schizophrenia (which can include apathy and inability to experience pleasure) compared to the group taking only clozapine. The larger 2g dose also improved positive symptoms of schizophrenia (such as hallucinations or delusions) and quality of life. Changes in levels of the antioxidant catalase were linked to the total improvement in symptoms and the improvement in positive symptoms. Sodium benzoate did not seem to cause any side effects.
Editor’s Note: Sodium benzoate is a D-amino acid oxidase inhibitor that activates NMDA receptors and increases levels of the amino acid D-serine in the brain by preventing it from breaking down. D-serine can reverse the effects of the illicit drug PCP, and very high doses of D-serine have improved the effectiveness of atypical antipsychotics in people with schizophrenia. By increasing levels of D-serine, sodium benzoate may offer new benefits to people with schizophrenia, especially those who have not responded to other treatments.
20-Year Study Finds Clozapine and Long-Acting Injectable Antipsychotics Most Effective at Preventing Re-Hospitalizations for Schizophrenia
Few studies have evaluated the comparative long-term effectiveness of antipsychotics in preventing relapse, but a 2017 study from Finland published in the journal Schizophrenia Bulletin by Heidi Taipale and colleagues did just that, and found that clozapine and long-acting injectable antipsychotic drugs were most effective at preventing psychiatric re-hospitalizations.
The Finnish health care registry was used to prospectively collect data on the treatment of every person who received inpatient care for schizophrenia between 1972 and 2014. The patients totaled 62,250 including 8,719 in their first episode of schizophrenia. Follow-up to evaluate antipsychotic use began at 1996 for those with ongoing treatment, and upon first discharge from the hospital for those patients in their first episode. The follow-up time ranged from 6.9 to 20 years with an average of 14.1 years. During the follow-up period, 59% of patients were readmitted to psychiatric inpatient care.
Among the drugs with the lowest rates of relapse, olanzapine long-acting injection, clozapine, and paliperidone long-acting injection were associated with the least risk of psychiatric re-hospitalization. Among patients in a first episode, taking flupentixol long-acting injection, olanzapine long-acting injection, or perphenazine long-acting injection had the lowest risk of psychiatric re-hospitalization. Clozapine and the long-acting injections also had the least risk of hospitalization for any cause.
Liraglutide Decreased Body Weight, Improved Glucose Tolerance and Cardio Health in Schizophrenia
A 2017 article by Julie R. Larsen and colleagues in the journal Archives of General Psychiatry reported that the drug liraglutide, a treatment for type 2 diabetes, improved certain health measures in people with schizophrenia who were overweight and prediabetic and being treated with the atypical antipsychotics olanzepine or clozapine.
In the 16-week trial, patients received a daily 2 mg injection of liraglutide under the skin or placebo. Liraglutide decreased body weight, improved glucose tolerance, and improved cardio-metabolic measures. Weight decreased by more than 10 pounds on average compared to placebo.
Liraglutide is derived from a human metabolic hormone. It binds to the same receptors as does the metabolic hormone GLP-1, which stimulates insulin secretion.
Solutions for Clozapine-Induced Drooling
Clozapine is a treatment for schizophrenia and treatment-resistant bipolar disorder. Drooling is a side effect for about one-third of people taking clozapine. Here are some treatments that may help reduce it:
1) Botox injected into each salivary (parotid) gland in doses of 50 IU.
2) Ipratropium, either sprayed under the tongue or intranasally. A 2004 case series by Oliver Freudenreich in the Journal of Clinical Psychiatry described sublingual administration.
3) Glycopyrrolate. In a 2011 article in the Annals of Pharmacotherapy, AM Bird described some treatments for clozapine-induced drooling, including glycopyrrolate.
4) The blood pressure drugs clonidine (50–100 mg) or terazosin.
4) Transdermal scopolamine patch. This is typically placed behind the ear to reduce motion sickness, but it also reduces saliva production.
Clozapine-Induced Myocarditis More Common Than Thought
New research indicates that myocarditis, inflammation of the middle layer of the heart wall, occurs in about 3% of patients who begin taking clozapine (Clozaril). Researcher Kathlyn J. Ronaldson and colleagues recently published research to this effect in the journal Acta Psychiatrica Scandinavica. Many cases of myocarditis, which can be fatal, begin with fever. Other symptoms include rapid or abnormal heart rhythms, shortness of breath, fluid retention, and fatigue. Because the illness resembles a viral infection, it may be misdiagnosed.
In 2010 Ronaldson and colleagues reported in the Journal of Clinical Psychiatry that tachycardia (rapid resting heart rate) and elevated levels of a group of proteins knows as troponin in the blood are almost always present during the first 45 days of treatment in patients who develop myocarditis. The researchers found that the time to onset of myocarditis was 14 to 22 days in almost all cases. Eosinophilia (high levels of a certain type of white blood cell) may occur in the week after peak troponin levels, and high levels of the inflammatory protein CRP (above 100mg/L) occurred in 79% of cases.
Ronaldson and colleagues suggest that patients who are prescribed clozapine be monitored for myocarditis during the first four weeks of treatment, particularly during the third week.
