Insect Repellants

Jun 18, 2018

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

``No good deed goes unpunished`` and ``I really have to pee.`` These were my thoughts just before the purple goo exploded all of the compounding hood. I was at work early to compound a sedative for a child who was going for a dental procedure that morning. And just as I was almost done drawing the grape flavored medication into little 1 mL oral syringes, I applied a little too much pressure. Sudddenly, grape medication sprayed all over the hood. ``No good deed goes unpunished``. So I started again. Then I stopped because I really had to pee. After getting back, I garbed up again for the hood. ``Why me?" "No good deed goes unpunished"

May was hot and dry. June is starting out wet. One more thing for me to complain about. Also hot then wet is the perfect recipe for everyone's favorite flying phlebotomists. Summer heat and standing water is just what the mosquitoes were waiting for. If you go outside, Manitoba's unofficial bird is going to get you.

What should you know to duck the droning little vampires? Avoidance and physical barriers are the first line of defense. Try to reduce the amount of time you spend outdoors around sunset and sunrise. These are the peak hours for mosquito activity. Fortunately, right now that is 5:30 am and 10:30 pm. Make sure the screens on your doors and windows don't have rips or tears. When possible wear long sleeved pants and shirts. Remove standing water from your property. That includes emptying children's wading pools, cleaning your eaves troughs, regularly emptying bird baths, and ensuring rain barrels are covered with a mosquito screen.

At the pharmacy, people often ask if it is safe to use a bug spray with DEET in it or if they should use something more natural, like citronella. My usual answer is that DEET has been shown to keep mosquitoes away from people and citronella doesn't have the evidence. Other alternative insect repellants like insecticide coils, ultrasonic devices, wrist bands and oral vitamin B1, don't have evidence for a good risk benefit ratio either. My wife loves the burning insecticide coil, and I don't think I'll ever be able to convince her they aren't awesome. So for you do-do coil fans, burn them outside in a well ventilated area. Remember insecticide means poison.

I like DEET as an insect repellant. DEET has been used for years and it works to keep mosquitoes away. It has a low chance of side effects. However, it is greasy, smelly and will eat plastic objects and clothing.

How do you use DEET safely? First remember that DEET is NOT recommended for children under 6 months of age. Physical barriers like screens are recommended. You can use 1 spray per day of 10 % or less DEET on children aged 6 months to 2 years of age if it is absolutely necessary. You can use DEET of 10% or less on children aged 2 to 12 years not more than 3 times per day. Over the age of 12 you can use DEET up to 30%.

What do the different percentages mean? The higher the percentage the more DEET could get absorbed through the skin, but the more mosquito repelling power the bug spray has. Here is what Health Canada says: repellents with concentration of DEET of 30% will protect you from mosquitoes for approximately 8 hours, DEET 20% for ~6 hours, and DEET 10% protects for about 4.5 hours.

There is a newer ingredient available in Canada. It is called icaridin. In the US it goes by the name picaridin. It is less greasy and smelly than DEET and is supposed to last longer at low concentrations than DEET. Several international bodies recommend it as a DEET alternative. However, there aren't many icaridin products in Canada yet. The icaridin product line we carry in the pharmacy is called Piactive.

Icaridin has recommended percentages too. Twenty percent icaridin protects for up to eight hours against ticks and black flies, and for up to seven hours against mosquitoes. The 20% icaridin is recommended for people 12 years of age and up. Ten percent icaridin protects for up to five hours against mosquitoes, and for up to seven hours against ticks. The 10% is recommended for kids 6 months up to 12 years old.

In the midst of feeling sorry for my self while cleaning up purple goo I said a bunch of bad words. Then I took a breath. Recently, there have been a couple of deaths and marriage break up or two amongst the people I know. I guess I still have my health, my family and a job I love. Despite the purple goo, things aren't that bad. But I'm still sure my good deed of this insect repellent article will punish me with a swam of mosquitos. And I'm always going to complain about those.

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.

We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at

For more information visit:

Health Canada's Insect Repellant Page:

Canadian Pediatric Society - Preventing insect and tick bites


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