 |
|
Dangerous interaction between the antibiotic ciprofloxacin and the muscle relaxant tizanidine
December 15, 2004Researchers from Finland have found that the antibiotic ciprofloxacin (brand names Ciproxin, Ciprofloxacin etc.) greatly increases the concentrations of tizanidine (Sirdalud, Zanaflex) in blood. Concomitant use of ciprofloxacin and tizanidine results in severe and prolonged decrease in blood pressure and greatly enhances central nervous system effects.
This previously unrecognised interaction can be dangerous, particularly in elderly patients, and the concomitant use of the two agents must be avoided. Tizanidine is widely used for treatment of musculoskeletal pain associated with increased muscle tension or chronic spasticity.
The concentrations of tizanidine in blood were increased on average 10-fold by ciprofloxacin in a carefully controlled study in healthy volunteer subjects. The volunteers ingested the usual 500-mg dose of ciprofloxacin (or placebo) twice daily for 3 days, and then a single 4-mg dose of tizanidine. The interaction was observed in each of the ten subjects; the greatest increase in tizanidine concentration by ciprofloxacin was 24-fold.
Ciprofloxacin enhanced greatly also the effects of tizanidine. In particular, the decrease in systolic ("upper") blood pressure, to the level of 90-mm Hg or even less, was an alarming finding. Such hypotension can be dangerous, eg in elderly subjects and in patients who have heart problems. Also the central nervous system effects of tizanidine were greatly enhanced by ciprofloxacin: all ten subjects were somnolent and dizzy for about 3 hours after tizanidine intake.
The interaction results from inhibition of the liver metabolism of tizanidine by ciprofloxacin. The same mechanism causes a serious interaction also between the antidepressant fluvoxamine and tizanidine, which was uncovered earlier this year. Further studies are being carried out to study whether there are other unrecognised interactions between tizanidine and other drugs.
The study was conducted at the Department of Clinical Pharmacology, University of Helsinki, by an independent group of researchers led by Professor Pertti J Neuvonen, MD, PhD, and Dr. Janne T Backman, MD, PhD. The study was published in the December issue of Clinical Pharmacology & Therapeutics, the leading scientific journal within the clinical pharmacology and therapeutics area.
Helsingin yliopisto (University of Helsinki)
Science Research Departments
Earth Science
Alternative Energy | Anthropology and Archaeology | Earthquakes and Volcanoes | Environment and Nature News | Global Warming | High-Energy and Particle Physics | Ozone Hole | Scientists Slow Light | Tsunami
Space Science
Astronomy and Space News | Black Holes | Chandra X-Ray Observatory | Extrasolar Planets | Hubble Telescope | International Space Station | Jupiter Galileo Mission | Jupiter Cassini Mission Flyby | Mars Exploration | Mars Odyssey 2001 | Mars Global Surveyor | Mars Polar Lander | Mars Climate Orbiter | Mars Pathfinder | Meteors and Asteroids | Mir Space Station | NEAR Asteroid Probe Mission | Pluto Planet Debate | Search for Extraterrestrial Life | Space Shuttle Program | Space Shuttle Mission: STS-102 | Space Weather
Life Science
Animal News | Biotechnology and Genetics | Brain Research | Human Cloning | Dinosaur and Fossil Discoveries | Endangered Species | Gene Therapy | Genetically Modified Food | Stem Cell Research | Whales and Whaling
 |
Scientific Explorer's Mind Blowing Science Kit for Young Scientists by Scientific Explorer Mind blowing experiments to delight and educate young scientists! Erupt a color changing volcano. Mix up magic ooze with a mind of its own. Play with sand that never gets wet. Mix safe chemicals and watch colors change before your eyes. You'll amaze yourself and your friends as you explore the science behind these truly remarkable reactions. |
 |
The Everything Kids' Science Experiments Book: Boil Ice, Float Water, Measure Gravity-Challenge the World Around You! (Everything Kids Series) by Tom Robinson (Author) Science has never been so easy - or so much fun! With The Everything Kids' Science Experiments Book, all you need to do is gather a few household items and you can recreate dozens of mind-blowing, kid-tested science experiments. High school science teach Tom Robinson shows you how to expand your scientific horizons - from biology to chemistry to physics to outer space. You'll discover answers to questions like: Get ready to enter the laboratory and learn how to conduct cool experiments, understand scientific terms... |
 |
Scientific Explorer's Disgusting Science - A Kit for Studying the Science of Revolting Things by Scientific Explorer Grow your own friendly germs and fuzzy molds. Mix up a batch of coagulating fake blood. Even make a stinky intestine. learn the science behind unmentionable bodily functions while doing some truly NASTY Experiments. Ages 8+ |
 |
The Science Book: Everything You Need to Know About the World and How It Works (National Geographic) by National Geographic (Author), Marshall Brain (Foreword) A delight for the casual reader, yet so complete and wide-ranging that science buffs and students will welcome it, The Science Book encapsulates centuries of scientific thought in one richly illustrated volume. Natural phenomena, revolutionary inventions, and the most up-to-date investigations are explained in detailed text, and 2,000 vivid illustrationsincluding 3-D graphics and pictogramsmake the information even more accessible and amazing to discover. The Science Book offers both a general overview of topics for the browsing reader and more specific information for those seeking deeper insight into a particular subject. Six major sections, ranging from the universe and planet Earth to biology, chemistry, physics, and mathematics, encompass everything from microscopic life... |
 |
Scientific Explorer's The Magic Science Wizard's Kit by Scientific Explorer Cast real smoke from your fingertips, make a wizard wand, and whip up color-changing potions in your test tube laboratory. Also included are laminated cards with wizard facts, an instruction booklet with 11 activities, lab equipment, and mysterious wizard powders that will mix together to mystify you! |
 |
Scientific Explorer's Tasty Science Chemistry in the Kitchen Kit by Scientific Explorer Who knew science could taste so good? With this kit, you’ll whip up cupcakes, cookies, candy, and more—all in the name of science! Learn what makes cakes rise, candy crystallize, and more real chemistry happen in the kitchen. Tasty Science is packed with ingredients, recipes, activity cards, a test tube laboratory, and lots more to explore the science of taste. |
 |
The Complete Book of Science, Grades 5-6 by School Specialty Publishing (Author) The Complete Book of Science for grades 5 to 6 teaches children important science skills!
Children complete a variety of exercises that help them develop a number of skills in this 352 page workbook. Including a complete answer key this workbook features a user-friendly format perfect for browsing, research, and review.
Over 4 million in print! The best-selling Complete Book series offers a full complement of instruction, activities, and information about a single topic or subject area. Containing over 30 titles and encompassing preschool to grade 8 this series helps children succeed in every subject area! ... |
 |
Magic School Bus Journey into the Human Body Science Kit by Young Scientist Club The Magic School Bus and Ms. Frizzle take Young Scientists on a wild ride into the human body with these breathtaking experiments. Young Scientists bend bones, make joints, map taste buds, expand lungs, build a stethoscope, measure lung capacities and heart rates, perform the iodine starch test, spin glitter, simulate synovial fluid, create a human body poster, and much, much more! This exciting kit includes a life-size poster with eight sheets of body part stickers. So put on your seat belts, students, and get ready to discover The Human Body! |
 |
What Is the World Made Of? All About Solids, Liquids, and Gases (Let's-Read-and-Find-Out Science, Stage 2) by Kathleen Weidner Zoehfeld (Author), Paul Meisel (Author) Did you ever walk through a wall? Drink a glass of blocks? Have you ever played with a lemonade doll, or put on milk for socks? This latest addition to the Let's-Read-and-Find-Out Science series introduces the youngest readers to an important science concept: the differences between solids, liquids, and gases. Any child who wants to know why he can't walk through a wall will enjoy Kathleen Zoehfeld's simple text and Paul Meisel's playful illustrations. |
 |
Scientific Explorer's Spa Science Chemistry Kit by Scientific Explorer Whip your bath into a frothy fizzing sea of color and fragrance. Make colorful, fragrant bath gels, bath fizzers, spa lotion, bath balm, a face mask, and shampoo. Mix colors and fragrances to creat your own product line with secret and exclusive mixtures. Explore the science of gels, fragrance and fizzers. |
| © 2009 BrightSurf.com |