By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy
We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca
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.
“The TV said my antidepressant is going to give me cancer. Is that true?” The best questions in the pharmacy always come from you, the public. After I got a little bit of background information like who the person was, what antidepressant they were on and what they saw on TV, I was able to reassure the person they were going to be okay. But I thought some of the research I had to read to answer the question was interesting.
The excitement all started with a paper published in the Feb 2010 edition of the British Medical Journal. Catherine M Kelly et al. looked at women 66 years old and over treated with tamoxifen for breast cancer at the same time they were taking one SSRI between 1993 and 2005. An SSRI or selective serotonin reuptake inhibitor is a type of antidepressant. The study included 2430 women. What the researchers were looking for was how many women died after their treatment with tamoxifen was over. Then they looked to see if the number of women who died increased if the time the women were on both tamoxifen and an SSRI increased. The answer is yes if a women is on tamoxifen and one type of SSRI called paroxetine or Paxil at the same time during breast cancer treatment, the women is more likely to die after the treatment. And yes, the longer the woman was on both paroxetine and tamoxifen during the cancer treatment, the more likely she is to die after the treatment was over. But, before everyone panics, let’s do some pharmacology.
Tamoxifen was originally developed from the bark of the Pacific Yew tree. (See I’m not against all natural products). It can be used for different things but most often it is used to prevent or treat breast cancer. Tamoxifen is called a Selective Estrogen Receptor Modulator or SERM. It binds to estrogen receptors in the body and prevents estrogens from having its regular effects. On the negative side, that means it causes hot flashes in women that are very similar to those experienced during menopause. On the positive sign if the women has a tumor in her breast that grows when it is given estrogen, the tamoxifen prevent estrogen from making the tumor grow.
Tamoxifen is also a pro-drug. That means the molecule tamoxifen doesn’t actually do anything in the body. It has to be converted to the metabolite endoxifen by an enzyme in the body called cytochrome P450 2D6 (CYP2D6). It is the endoxifen that fights cancer. So if someone didn’t have functioning CYP2D6 then tamoxifen wouldn’t work for them. Apparently about 7% of us don’t have functional CYP2D6 enzymes. So if you give a women without functional CYP2D6 enzymes to treat her breast cancer, it won’t help her.
In the BMJ study they looked at SSRI’s like paroxetine, because paroxetine stops CYP2D6 from working. Based on the results, the study’s authors estimate that if 20 women took paroxetine at the same time as their tamoxifen 41% of the time during breast cancer treatment that one woman more than expected would die from breast cancer at 5 years after treatment. This is an important finding, but remember the study wasn’t perfect. It only looked at women over 66 years old. The authors didn’t do genetic testing, so they don’t know how many patients naturally had CYP2D6 enzymes that didn’t work. Were women with more severe breast cancer more depressed, so they got paroxetine more often?
If you are on paroxetine and tamoxifen right now, don’t panic. Don’t stop taking either drug. At your next appointment, talk to your doctor about options. We can switch the antidepressant to another one that doesn’t block CYP2D6. Two options are citalopram and venlafaxine. We can switch your tamoxifen to estrogen blockers that aren’t prodrugs. The have names like arimidex. These aromatase inhibitors are more potent and expensive than tamoxifen and they aren’t appropriate for younger women.
As always if you have any questions or concerns about these or other products, ask your pharmacist.
Friday, February 19, 2010
Friday, February 12, 2010
Measles, Mumps and Rubella Vaccine
By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy
We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca
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.
One of my favourite TV shows was the X-files. It wasn’t just because it came on Sunday nights when I was supposed to be studying. I loved watching FBI Agents Mulder and Scully tracking down UFO’s, government conspiracies, ghosts and aliens. There was the “Cigarette Smoking Man” whose name we never learned but who periodically gave our daring duo tips about the UFO related Black Ops the government was up to. The tag line for the show was “The Truth is Out There”.
I couldn’t help but think that the truth might be out there in Newfoundland recently. Residents of Harbour Mille, Newfoundland reported seeing a UFO flying over their community Monday, January 25, 2010. The UFO pictures I saw were taken by Harbour Mille resident Darlene Stewart. The UFO looked missile-like to me. However the Prime Minister’s Office and Department of National Defence denied that any missile was fired. I thought the story felt very X-Files-ish. The problem is that if you are always chasing UFO’s and government conspiracies, sometimes you miss the truth that is out there right in front of your nose. One recent conspiracy theory said that the Measles, Mumps, and Rubella or MMR vaccine caused autism. The truth on that conspiracy became even more clear recently and not everyone will be happy.
The MMR vaccine prevents three different viral diseases. Measles, mumps and rubella have no effective treatments once a patient is infected. However, they can be prevented by getting the vaccine before exposure to the virus.
Measles is not a deadly disease in most people. It causes a rash, fever, runny nose and cough that lasts one to two weeks. Why vaccinate against it then? Because large outbreaks of the disease usually happen in children. A small percentage of these children develop meningitis, an inflammation of the brain and spinal cord that can cause headaches, seizures, coma and/or long term brain damage. In rare cases it can even cause death.
Mumps is an uncomfortable condition. It can cause painful, swollen saliva glands (usually in the cheeks) and fever. Painful inflammation of the testicles can occur in 1 out of 4 boys beyond puberty and painful inflammation of the ovaries in about 5% of girls beyond puberty. Again brain lining inflammation (or meningitis) is a rare but serious possibility.
Rubella is an important disease to avoid during pregnancy, as it can damage the unborn baby. Rubella can cause brain damage, an unusually small head, deafness, heart defects, blindness, small eyes, diabetes or death in the unborn child. About 90% of women infected with rubella during the first trimester of pregnancy will give birth to babies with problems. So it is important to try to protect all children at a young age from rubella so they don’t contract the disease when they get pregnant later in life or give the disease to a pregnant woman.
The MMR vaccine is very effective. It protects 94% of those immunized verses rubella, 81% verses mumps and 88% verses measles. Measles protection goes up to 99% after two vaccinations. Protection is believed to be lifelong in most people for all three diseases. So where does the MMR vaccine-autism link come from?
Back in 1998 there was a study published in the Lancet by Dr. AJ Wakefield and colleagues. They looked at 12 children that had lost acquired skills like language. These children ranged in age from 3 to 10 years and 11of the 12 were boys. These children could have had Autism Spectrum Disorder, depending on how that condition is defined. Of these 12 children, eight of them had developed autism like symptoms after the MMR vaccine as determined by the parents. So the controversy began.
What was wrong with people questioning MMR vaccine after those reports? Nothing. But the popular media seemed to ignore that the study was only a study of 12 children, not the 1000’s of people that we usually like to see in a study. The celebrities who announced MMR causes autism seemed to ignore that since 1998 at least a dozen studies looked for a connection between MMR and autism and found none. Now the original publisher, the Lancet, has actually retracted the original study. On February 2, 2010 the Lancet published a short retraction that said in part “Following the judgment of the UK General Medical Council’s Fitness to Practise Panel on Jan 28, 2010, it has become clear that several elements of the 1998 paper by Wakefield et al are incorrect…Therefore we fully retract this paper from the published record.”
So the system worked, right? The flawed paper was eventually pulled and now everyone knows the MMR vaccine doesn’t cause autism. Well, unfortunately due to some celebrity endorsements, I think some people will always believe MMR is a conspiracy to cause autism. The original author, Dr. Wakefield and has said the Panel’s findings were “unjust and and unfounded”. But more importantly because fewer parents gave their children the MMR vaccine in the last 12 years, there will be more outbreaks of measles, mumps and rubella.
You don’t believe me? Well in 2004-2005 there was a mumps epidemic in the United Kingdom. The highest rate of infection was among those born during 1983-1986. People in England and Wales born before 1987 were generally not eligible for a mumps vaccine. Only 2.4% of confirmed cases of mumps during the 2004-2005 outbreak would have been eligible for the routine 2 doses of MMR vaccine. There were probably other factors involved, but this seems a clear case of people who didn’t get a mumps vaccine getting sick more often than would be expected.
So the truth is still out there. However in ten to twenty years the conspiracy might be the autism-MMR scare of the late 1990’s, and early 2000’s lead to a lot of pain, suffering and possible death due to measles, mumps and rubella.
UFO in Newfoundland link : http://www.cbc.ca/canada/newfoundland-labrador/story/2010/01/28/ufo-newfoundland-pmo.html
Lancet retraction link: http://download.thelancet.com/flatcontentassets/pdfs/S0140673610601754.pdf
As always if you have any questions or concerns about these or other products, ask your pharmacist.
We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca
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.
One of my favourite TV shows was the X-files. It wasn’t just because it came on Sunday nights when I was supposed to be studying. I loved watching FBI Agents Mulder and Scully tracking down UFO’s, government conspiracies, ghosts and aliens. There was the “Cigarette Smoking Man” whose name we never learned but who periodically gave our daring duo tips about the UFO related Black Ops the government was up to. The tag line for the show was “The Truth is Out There”.
I couldn’t help but think that the truth might be out there in Newfoundland recently. Residents of Harbour Mille, Newfoundland reported seeing a UFO flying over their community Monday, January 25, 2010. The UFO pictures I saw were taken by Harbour Mille resident Darlene Stewart. The UFO looked missile-like to me. However the Prime Minister’s Office and Department of National Defence denied that any missile was fired. I thought the story felt very X-Files-ish. The problem is that if you are always chasing UFO’s and government conspiracies, sometimes you miss the truth that is out there right in front of your nose. One recent conspiracy theory said that the Measles, Mumps, and Rubella or MMR vaccine caused autism. The truth on that conspiracy became even more clear recently and not everyone will be happy.
The MMR vaccine prevents three different viral diseases. Measles, mumps and rubella have no effective treatments once a patient is infected. However, they can be prevented by getting the vaccine before exposure to the virus.
Measles is not a deadly disease in most people. It causes a rash, fever, runny nose and cough that lasts one to two weeks. Why vaccinate against it then? Because large outbreaks of the disease usually happen in children. A small percentage of these children develop meningitis, an inflammation of the brain and spinal cord that can cause headaches, seizures, coma and/or long term brain damage. In rare cases it can even cause death.
Mumps is an uncomfortable condition. It can cause painful, swollen saliva glands (usually in the cheeks) and fever. Painful inflammation of the testicles can occur in 1 out of 4 boys beyond puberty and painful inflammation of the ovaries in about 5% of girls beyond puberty. Again brain lining inflammation (or meningitis) is a rare but serious possibility.
Rubella is an important disease to avoid during pregnancy, as it can damage the unborn baby. Rubella can cause brain damage, an unusually small head, deafness, heart defects, blindness, small eyes, diabetes or death in the unborn child. About 90% of women infected with rubella during the first trimester of pregnancy will give birth to babies with problems. So it is important to try to protect all children at a young age from rubella so they don’t contract the disease when they get pregnant later in life or give the disease to a pregnant woman.
The MMR vaccine is very effective. It protects 94% of those immunized verses rubella, 81% verses mumps and 88% verses measles. Measles protection goes up to 99% after two vaccinations. Protection is believed to be lifelong in most people for all three diseases. So where does the MMR vaccine-autism link come from?
Back in 1998 there was a study published in the Lancet by Dr. AJ Wakefield and colleagues. They looked at 12 children that had lost acquired skills like language. These children ranged in age from 3 to 10 years and 11of the 12 were boys. These children could have had Autism Spectrum Disorder, depending on how that condition is defined. Of these 12 children, eight of them had developed autism like symptoms after the MMR vaccine as determined by the parents. So the controversy began.
What was wrong with people questioning MMR vaccine after those reports? Nothing. But the popular media seemed to ignore that the study was only a study of 12 children, not the 1000’s of people that we usually like to see in a study. The celebrities who announced MMR causes autism seemed to ignore that since 1998 at least a dozen studies looked for a connection between MMR and autism and found none. Now the original publisher, the Lancet, has actually retracted the original study. On February 2, 2010 the Lancet published a short retraction that said in part “Following the judgment of the UK General Medical Council’s Fitness to Practise Panel on Jan 28, 2010, it has become clear that several elements of the 1998 paper by Wakefield et al are incorrect…Therefore we fully retract this paper from the published record.”
So the system worked, right? The flawed paper was eventually pulled and now everyone knows the MMR vaccine doesn’t cause autism. Well, unfortunately due to some celebrity endorsements, I think some people will always believe MMR is a conspiracy to cause autism. The original author, Dr. Wakefield and has said the Panel’s findings were “unjust and and unfounded”. But more importantly because fewer parents gave their children the MMR vaccine in the last 12 years, there will be more outbreaks of measles, mumps and rubella.
You don’t believe me? Well in 2004-2005 there was a mumps epidemic in the United Kingdom. The highest rate of infection was among those born during 1983-1986. People in England and Wales born before 1987 were generally not eligible for a mumps vaccine. Only 2.4% of confirmed cases of mumps during the 2004-2005 outbreak would have been eligible for the routine 2 doses of MMR vaccine. There were probably other factors involved, but this seems a clear case of people who didn’t get a mumps vaccine getting sick more often than would be expected.
So the truth is still out there. However in ten to twenty years the conspiracy might be the autism-MMR scare of the late 1990’s, and early 2000’s lead to a lot of pain, suffering and possible death due to measles, mumps and rubella.
UFO in Newfoundland link : http://www.cbc.ca/canada/newfoundland-labrador/story/2010/01/28/ufo-newfoundland-pmo.html
Lancet retraction link: http://download.thelancet.com/flatcontentassets/pdfs/S0140673610601754.pdf
As always if you have any questions or concerns about these or other products, ask your pharmacist.
Friday, February 05, 2010
Antihistamines - AUDIO
Click to hear Trevor's Pharmacy Feature-Audio Segment Thanks to all the good people at the Parkland's Best Music 730 CKDM Return to Dauphin Clinic Pharmacy site
Antihistamines
By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy
We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca
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.
“Na Na-Na Na Na. Thunder. Na Na-Na Na Na. Thunder.” The opening bars of AC/DC’s Thunder Struck played over the speakers as the Parkland Source for Sports Thunder whizzed around the Ste Rose arena warming up. Okay whizzed around might be a little strong. Rode their sticks like ponies, ambled aimlessly, and made the occasional snow angel on the ice is more accurate, but the Source For Sports Thunder Novice team eventually got started on their warm up drills. The seven and eight year old mostly boys and a couple of girls like my daughter on the Thunder were psyching up to play the mighty McCreary Mustangs. I was lost in thought about how cool it would have been if my seven year old friends and I had a theme song playing over the speakers when we played hockey way back when. Anthony Wiens was remarking how cold it was in the Ste. Rose rink eventhough it was up to -3 C outside. Then he noted that not all music was created equal. He said it was funny how the older rock songs just seemed to suit hockey games better than newer music. And as I listened to the songs during the breaks in play, I began to think he was right. Different pop music has different uses.
If you get an allergic reaction, one of the types of medication we reach for are antihistamines. Not all medications that block histamine are created equal either. Histamine blockers that block the H2 histamine receptor don’t even treat allergies. They have names like ranitidine and actually are used to reduce stomach acid and treat heart burn and ulcers. For our purposes, H2 blockers are like classical music, interesting but irrelevant for a discussion of pop music. For allergies, we want H1 receptor blockers which are usually just called antihistamines.
Allergic reactions start more or less the same way. When your body comes in contact with what you are allergic to (the allergen), certain cells in your immune system release a chemical messenger called histamine. The histamine connects with the H1 histamine receptor and tells your body to start the allergy symptoms, like the runny nose, or the itchy rash. So the easiest and best way to avoid an allergic reaction is to identify and avoid the allergen. If you are allergic to the cat at your mother-in-law’s house, avoid your mother-in-law. If that horrible cologne your wife bought gives you an itchy rash, don’t use it. Simple, right? Well, even if we can identify the allergen, sometimes they are hard to avoid. If you are allergic to pollens that are common in Manitoba, you will probably get a stuffy nose in the fall no matter what you do. So if we can’t identify and avoid the allergen, we may need to block the H1 histamine receptor with a medication.
There are two basic types of antihistamines. The first generation antihistamines are have names like chlortripolon (chlorpheniramine), and benadryl (diphenhydramine). They are inexpensive, work quite well, but they also often cause drowsiness, and some other side effects like urinary retention, and worsening glaucoma. They work fast, which is great if you have an itchy rash, but they don’t last that long and you may have to take several pills a day. So they are cheap and fast, but have no staying power and might bore you to sleep. So, let’s call first generation antihistamines dance music.
Second generation antihistamines cause much less sedation, have far fewer side effects, but they are more expensive. These are agents like reactine (cetirizine), and claritin (loratadine). A nice benefit is one pill often lasts all day. Reactine is good for both runny noses and itchy rashes, but I have seen it make some people sleepy. Claritin only works well on runny noses, but it is much less likely to make someone sleepy. So they are more expensive, but have fewer side effects and more staying power. So, let’s call second generation antihistamines classic rock.
So, different antihistamines have different uses. Classic rock is what should be played during breaks at hockey games. Any beware the Source For Sports Thunder. Or you’ll be Thunder Struck!
As always if you have any questions or concerns about these or other products, ask your pharmacist.
We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca
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.
“Na Na-Na Na Na. Thunder. Na Na-Na Na Na. Thunder.” The opening bars of AC/DC’s Thunder Struck played over the speakers as the Parkland Source for Sports Thunder whizzed around the Ste Rose arena warming up. Okay whizzed around might be a little strong. Rode their sticks like ponies, ambled aimlessly, and made the occasional snow angel on the ice is more accurate, but the Source For Sports Thunder Novice team eventually got started on their warm up drills. The seven and eight year old mostly boys and a couple of girls like my daughter on the Thunder were psyching up to play the mighty McCreary Mustangs. I was lost in thought about how cool it would have been if my seven year old friends and I had a theme song playing over the speakers when we played hockey way back when. Anthony Wiens was remarking how cold it was in the Ste. Rose rink eventhough it was up to -3 C outside. Then he noted that not all music was created equal. He said it was funny how the older rock songs just seemed to suit hockey games better than newer music. And as I listened to the songs during the breaks in play, I began to think he was right. Different pop music has different uses.
If you get an allergic reaction, one of the types of medication we reach for are antihistamines. Not all medications that block histamine are created equal either. Histamine blockers that block the H2 histamine receptor don’t even treat allergies. They have names like ranitidine and actually are used to reduce stomach acid and treat heart burn and ulcers. For our purposes, H2 blockers are like classical music, interesting but irrelevant for a discussion of pop music. For allergies, we want H1 receptor blockers which are usually just called antihistamines.
Allergic reactions start more or less the same way. When your body comes in contact with what you are allergic to (the allergen), certain cells in your immune system release a chemical messenger called histamine. The histamine connects with the H1 histamine receptor and tells your body to start the allergy symptoms, like the runny nose, or the itchy rash. So the easiest and best way to avoid an allergic reaction is to identify and avoid the allergen. If you are allergic to the cat at your mother-in-law’s house, avoid your mother-in-law. If that horrible cologne your wife bought gives you an itchy rash, don’t use it. Simple, right? Well, even if we can identify the allergen, sometimes they are hard to avoid. If you are allergic to pollens that are common in Manitoba, you will probably get a stuffy nose in the fall no matter what you do. So if we can’t identify and avoid the allergen, we may need to block the H1 histamine receptor with a medication.
There are two basic types of antihistamines. The first generation antihistamines are have names like chlortripolon (chlorpheniramine), and benadryl (diphenhydramine). They are inexpensive, work quite well, but they also often cause drowsiness, and some other side effects like urinary retention, and worsening glaucoma. They work fast, which is great if you have an itchy rash, but they don’t last that long and you may have to take several pills a day. So they are cheap and fast, but have no staying power and might bore you to sleep. So, let’s call first generation antihistamines dance music.
Second generation antihistamines cause much less sedation, have far fewer side effects, but they are more expensive. These are agents like reactine (cetirizine), and claritin (loratadine). A nice benefit is one pill often lasts all day. Reactine is good for both runny noses and itchy rashes, but I have seen it make some people sleepy. Claritin only works well on runny noses, but it is much less likely to make someone sleepy. So they are more expensive, but have fewer side effects and more staying power. So, let’s call second generation antihistamines classic rock.
So, different antihistamines have different uses. Classic rock is what should be played during breaks at hockey games. Any beware the Source For Sports Thunder. Or you’ll be Thunder Struck!
As always if you have any questions or concerns about these or other products, ask your pharmacist.
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