Antipsychotics and Schizophrenia
Aug 18, 2016
By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy
"That's not a strike! He didn't swing the bat." As usual, I'm failing as a parent. We went to a Goldeyes game in Winnipeg with my parents, sister, and brother-in-law. We had a great time, but it occurred to me early in the game, my kids know nothing about the basic rules of baseball. I played some ball as a kid, because everyone did, but I didn't love it and I wasn't terribly talented at it. Emily played some T-ball and softball, but it would be generous to say she was lukewarm about ball. Eric played two seasons of T-ball and hated it. It was too slow, not enough action and there was even a physical altercation when Eric caught a ball that a teammate thought was his. After the two were separated, the mothers made the two boys hug and say they were sorry. You could tell Eric was still mad that he got punched in the head for catching a ball and wasn't happy he was forced to say he was sorry. And I couldn't blame him. Long story short, my kids don't play ball. So it shouldn't have surprised me they had no idea what was going on at the Goldeyes game.
A mental health condition many people don't know much about is schizophrenia. A new drug for schizophrenia is making the news. It is called Invega Trinza. I can't remember the last time a schizophrenia medication made it into the main stream news. Chris Summerville, the Executive Director of the Manitoba Schizophrenia Society, was quoted in different media saying he was excited because this long acting medication should help people with schizophrenia remember to take their medication and thus have fewer relapses. That is good news. However, Invega Trinza isn't really brand new. And just because Health Canada approved it for sale, that doesn't necessarily mean Manitoba Health will agree to pay for it. And it will probably be very expensive.
Because many people aren't familiar with schizophrenia or the medications to treat it, let's do a very brief review of a huge subject. Schizophrenia affects the brain. The brain is so enormously complex that we really only understand a fraction of how it works. One thing we do know is all the nerve cells, or neurons, in the brain don't actually touch each other. They are separated by tiny gaps called synapses. An electrical nerve signal travels down the dendrites of one neuron, through the cell body and then down the axon. But the axon is separated from the dendrite of the next neuron by a synapse or gap. The end of the axon of the first neuron must produce a chemical called a neurotransmitter which moves across the synapse, and hooks onto receptors on the dendrite of the next neuron. Then the electrical signal continues down the next neuron. These synapses between neurons are very important in pharmacy world, because that is where almost all our mental health drugs act.
Schizophrenia is a group of disorders involving the disruption of thought, behaviour, how happy or sad we feel and a how we perceive the world. It effects about 1 in 100 people in Canada. It can affect men and women and it often strikes between 15 and 25 years old. We don't know all of what is going wrong in the brain in schizophrenia, but we believe there is too much of the neurotransmitter or brain signal called dopamine in the part of the brain called the meso-limbic section.
Many schizophrenia medications, which are often called antipsychotics, try to block dopamine in the meso-limbic system. The first successful antipsychotics were developed in the 1950's. They worked really well for the positive symptoms of schizophrenia like hallucinations and delusions. They didn't work as well on the negative symptoms like lack of pleasure in life, not displaying emotions and lack of speech. And they had lots of side effects like sedation, dry mouth, blurred vision, constipation, problems urinating, Parkinson like effects, heart problems and weight gain. A common medication in these original group of antipsychotics is haloperidol or haldol.
A newer group of antipsychotics, second generation antipsychotics or atypical antipsychotics were developed over the past 2 decades. They seem to block serotonin as well as dopamine. These atypical antipsychotics work as well as haloperidol on hallucinations and delusions. They seem to cause less Parkinson like movement problems. They work better than the original antipsychotics on negative schizophrenia symptoms like lack of pleasure in life, not displaying emotions and lack of speech. All the new atypical antipsychotics are expensive. Depending on the agent, the atypical antipsychotic can cause weight gain, diabetes, cholesterol problems, effect heart rhythm or be sedating. Common agents are aripiprazole, abilify, olanzapine, zyprexa, quetiapine, seroquel and risperidone.
Paliperidone is a newer one of these atypical antipsychotics. On the plus side it only has a moderate risk of causing weight gain and a low risk of causing diabetes or cholesterol problems. It still can cause dangerous heart rhythm problems. The brand name of paliperidone is Invega. Invega is available as an oral pill which is taken everyday and will cost over $200 per month. Invega Sustenna is an injectable form of paliperidone. Each Invega Sustenna shot will last about a month and will cost closer to $600. Invega Trinza still contains the same medication, paliperidone, but each shot will last 3 months. It will be expensive. It will be good that people with schizophrenia who take Invega Trinza will only need 4 shots a year. But like other long acting medications that means potential side effect will last 3 months as well. So it would be best if a patient started out on the daily pill version for several months, and then worked up to the monthly injection for several months before their doctor considered the new 3 month shot.
The Goldeyes game went surprisingly well. The kids seemed to pick of the basic rules of baseball quickly. Plus they saw a couple of double plays, a grand slam home run (for the other guys) and catcher get run over for blocking home plate. It was exciting and went to 11 innings. The score clock was out for a couple of innings, so the kids had to keep track of balls, strike and the score. At 11:45 pm the automatic sprinklers went on, doused the crowd and delayed the game a bit. But the Goldeyes pulled it out 16-15 and then there were fireworks. Maybe my kids won't be ball players, but maybe they just got converted to baseball fans.
Health Canada accepts Invega Trinza - http://www.hc-sc.gc.ca/dhp-mps/prodpharma/rds-sdr/drug-med/rds-sdr-invega-trinza-185929-eng.php
Manitoba Schizophrenia Society - www.mss.mb.ca
As always if you have any questions or concerns about these or other products, ask your pharmacist.
The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist or other health care professional.
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