Monday, August 31, 2015

Is coffee involved with calcium absorption?

Question: Coffee is involved with calcium absorption, is it yes or not?

Answer: Drinking one glass of 180 mg of coffee, it would lose the equilibrium of calcium to 4.3 mg.

The caffeine in coffee will reduce calcium absorption in the intestine. The caffeine is a mild diuretic and increase sodium excretion in the urine. As a result, calcium is drawn out in urine as well.

It is not found that coffee drinking has a negative effect on calcium balance if the calcium intake is not less than 600-800 mg per day.

However, coffee drinkers tend to avoid drinking milk (milk is one cause of reducing the absorption of calcium as well). In summary, when drinking lots of coffee, but not eating enough calcium, it may lose the balance of calcium.

Reference:

http://www.webmd.com/osteoporosis/living-with-osteoporosis-7/diet-dangers?page=2

Drug interaction between antibiotics and oral contraceptive

Question: What is the mechanism of drug interaction between antibiotics and oral contraceptives?


Answer: There are several mechanisms of drug interaction between antibiotics and oral contraceptives, depending on the type of antibiotics.

Such as:
Penicillins and Tetracyclines will reduce the absorption of oral contraceptives. By inhibiting bacteria in the intestine that affects an enzyme used in the process of enterohepatic recirculation. And it resulted in decrease in level of oral contraceptives.

Rifampicin is an enzyme inducer. It makes an enzyme in the liver to eliminate estrogenic and progestational component in oral contraceptives from the body faster.

References:

http://www.ncbi.nlm.nih.gov/pubmed/12063491

How can the cotton wool be used most effectively when it is moistened with alcohol?

Question: At what time should the cotton wool ball be used most effectively when it is moistened with alcohol?

Answer: Alcohol (ethyl alcohol, isopropyl alcohol) in the strength 70% in water is used to clean the wound.

Alcohol in the strength 70% in water has fast-acting bactericidal, but short-acting. It should be used immediately. Cotton wool moistened with alcohol should not be left for long, because alcohol evaporates quickly and will be diluted and less effective.

Alcohol acts by precipitation process of protein. Isopropyl alcohol is slightly more potent than ethyl alcohol. Some places may prepare the isopropyl alcohol slightly lower strength than ethyl alcohol. If the two kinds of alcohol were used in the equal strength, isopropyl alcohol may still be effective a little longer than ethyl alcohol.

However, it is recommended that cotton wool moistened with alcohol should not be left for too long. It should be used immediately, whether it is isopropyl alcohol or ethyl alcohol (or any other kinds of alcohol). And all of them should be kept in tightly closed containers.


Reference:
http://www.cdc.gov/niosh/pdfs/76-142b.pdf


Thursday, August 27, 2015

How long can the drug be stored after opening the container?

Question: How long can the drug for external use in the emergency room of the hospital (such as a bottle of 450 ml of povidone-iodine, alcohol, ammonia, gentian-violet) be stored at temperature room after opening the container?

Answer: Expiration date of pharmaceutical is the expected time of properties of pharmaceutical will be remained under storage condition as defined in the Pharmacopoeia. The expiry date determined by the manufacturer could not be applied as the expiry date of pharmaceuticals repacking in containers that are different from the original.

But another way to calculate an expiration date is beyond use date.

Beyond use date is the date that pharmaceuticals should not be used anymore. It is used to determine the age of pharmaceuticals in the following cases.  
        - Pharmaceutical formulations are prepared for use in hospital only.
     - The repacking from the container of manufacturer.
     - There is no information about the stability or expiry date of pharmaceuticals. .

The beyond use date of the pharmaceutical repacking should be given a period of 25% of the rest from the date of repacking until the expiration date of pharmaceutical product in the original container defined by the manufacturer, or generally six months after the date of repacking, by choosing a shorter period of time.

Example: Expiration date on the label that is defined by manufacturer is December 12, 2015. Date opening medication is December 12, 2014. The period from December 12 2014 to December 12, 2015 was a period of 12 months and 25% of 12 months is three months, so the expiration date should actually be three months from the date of opening the container, or it was April 12, 2015.

Pharmaceuticals are generally defined to expire six months after opening the container. But the method which gives the shorter expiry date generally should be selected to determine expiry date more than another method. So the expiry date of this example is three months, not six months.

However, consideration of the expiration of pharmaceuticals must regard the characteristics of pharmaceutical products such as changing color, turbidity or precipitation and etc. Because if external features of pharmaceutical products are changing, although they have not reached beyond-use date specified, the pharmaceutical products should not be used anymore.

In case of opening the container of povidone-iodine, alcohol, ammonia, gentian violet, They are determined the beyond use date, as well as pharmaceutical repacking, as mentioned above. Also keep these pharmaceutical products in the environment with temperature and humidity controlled as defined in the Pharmacopoeia or is listed on the label.

If there is no information about temperature and humidity of some pharmaceutical products, They are generally stored at room temperature that has relative humidity less than 75%, and they should be kept in their original container and cover tightly when not in use.

References:
1. Gennaro AR, editor. Remington: the science and practice of pharmacy. 20th ed. Philadelphia: Lippincott Williams & Wilkins; 2000.
2. Authority of the United States Pharmacopeial Convention. The United States Pharmacopeia, the national formulary: USP 23, NF 18 1995 / United States Pharmacopeial convention. Rockville (MD): The United States Pharmacopeial convention; 2000.





Wednesday, August 26, 2015

The method to calculate the expiry date of drug after opening the container.

Question: I want to know the stability and sterility of K-Y jelly after it is opened to use, and how long can K-Y jelly be stored at room temperature after opening?


Answer: K-Y jelly is a topical emollient formulation. The expiry date is  defined by the next six months after opening.


But another way to calculate an expiration date is beyond use date. Beyond use date is the date that pharmaceuticals should not be used anymore. The beyond use date of pharmaceutical packaging or after opening to use, is calculated from 25% of the rest from the date of opening the container until the expiration of pharmaceuticals in the original container labeled by the manufacturer.

Pharmaceuticals are generally defined to expire six months after opening the container. But the method which gives the shorter expiry date generally should be selected to determine expiry date more than another method.


Example: Expiration date on the label that is defined by manufacturer is December 12, 2015. Date opening medication is December 12, 2014. The period from December 12 2014 to December 12, 2015 was a period of 12 months and 25% of 12 months is three months, so the expiration date should actually be three months from the date of opening the container, or it was April 12, 2015. 

However, if pharmaceutical has changed from the original product such as color, smell and viscous. This may be due to improper drug storage. It makes the drug loses it's stability. Therefore the drug should not be used anymore, although it has not reached the calculated expiration date.

Reference:
1.Karpinski JP. Medication expiration dating. PharmacyTech News. 2011. Available onhttps://www.cedrugstorenews.com/userapp/lessons/page_view_ui.cfm?lessonuid=&pageid=98A4D0865060D9CDE96A50282801AE4D
2.Gennaro AR, editor. Remington: the science and practice of pharmacy. 20th ed. Philadelphia: Lippincott Williams & Wilkins; 2000.
3.Authority of the United States Pharmacopeial Convention. The United States Pharmacopeia, the national formulary: USP 23, NF 18 1995 / United States Pharmacopeial convention. Rockville (MD): The United States Pharmacopeial convention; 2000.

Tuesday, August 25, 2015

Will amoxicillin reduce effectiveness of oral contraceptive?

Question: I have a sore throat, swollen and purulent. The doctor prescribed me amoxicillin. But now I am taking oral contraceptives. 
Do I suspect that amoxicillin will reduce the effectiveness of oral contraceptive or not?

Answer: There is the data about drug interaction between contraceptive and amoxicillin that may reduce effectiveness of oral contraceptive.

In the past, a few clinical cases had been reported that had failure to prevent pregnancy when they ate amoxicillin with oral contraceptive. However, there is no study quality and reliable enough to be supported.

In such cases, if the patient becomes infectious diseases in the upper respiratory tract, which is necessary to take antibiotics. It is recommended that patient should be taking received amoxicillin.

If a patient is worry about the pregnancy, it is recommended to use oral contraceptive in combination with other method of contraception, such as the condoms, during taking amoxicillin and further seven days after finishing amoxicillin.

Reference:


1. Zhanel GG, Siemens S, Slayter K, Mandell L. Antibiotic and oral contraceptive drug interactions: Is there a need for concern? Can J Infect Dis 1999; 10 (6): 429-33.

Friday, August 21, 2015

Allopurinol and Colchicine in Gout

Question: When do we take allopurinol and colchicine in gout?

Answer: Colchicine is used for the treatment of acute gout attack by reducing pain and inflammation. The mechanism of action is unknown. It is believed that the drug involved in the reaction of the body to respond to the crystals of uric acid. The drug is used only for short periods and stopped when the pain relief. This drug does not slow the progress of gout.

Allopurinol is the drug that reduces uric acid levels in the blood. It inhibits xanthine oxidase which is enzyme in the process of producing uric acid. The Drug used in patients with high blood levels of uric acid, but no effective treatment for acute gout attack.


Reference:

Thursday, August 20, 2015

Norfloxacin and antacid

Question:
1. What is the reason why do not use norfloxacin with antacids.
2. Is it eaten with milk, yes or not?
3. The doctor prescribed this drug to me several times, each time I never take medicine out. What will happen and what effect is it?

Answer:
1. Antacid is the drug which contains aluminium, magnesium or calcium. They will reduce the absorption of drugs in group of fluoroquinolones (norfloxacin is in this group). So norfloxacin should not be eaten together with antacids.
Norfloxacin should eat at least two hours before or after eating antacids. The other drugs in fluoroquinolones may vary slightly. Mostly it is recommended to eat before antacids at least two hours, but period after taking antacids may be different, such as ciprofloxacin and lomefloxacin should be eaten after antacids for at least six hours.

2. Dairy products include milk and foods that are made from milk. And milk also contains high amounts of calcium. So, they can reduce the absorption of norfloxacin.
Norfloxacin should be taken before meals or milk products for at least one hour and after a meal or dairy products for at least two hours.


3. It is important to take all of your medication as instructed by your doctor, even if you are feeling better in a few days. Not finishing the complete dose of norfloxacin may decrease the drug's effectiveness and increase the chances for bacterial resistance to norfloxacin and similar antibiotic.

References:
The document recommended reading for the first answer.
1. http://www.drugs.com/MMX/Magaldrate.html
2. Nix DE, et al. Inhibition of norfloxacin absorption by antacids. Antimicrob Agents Chemother 1990; 34: 432-5

3. Minami R, et al. Effect of milk on absorption of norfloxacin in healthy volunteers. J Clin Pharmacol 1993; 33: 1238-40
4. http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a687006.ht

Sunday, August 16, 2015

ACEI , Microalbuminuria, Serum creatinine

Question: Antihypertensive (ACEI group) can slow the deterioration of the kidney in DM (diabetes mellitus) patients with renal impairment, is it true or not? And the microalbumin test has advantages over serum creatinine test, is it yes or not?

Answer: Currently, there is evidence believed that ACEI drugs can slow the deterioration of the kidneys as well as reducing the complications of the cardiovascular system in diabetes patients with microalbuminuria.

Microalbuminuria is a condition which albumin is excreted in the urine 30-300 mg / day. It is a sign of kidney dysfunction in the early stages that can be detected by common method.


Although, the serum creatinine will be monitored easily, but it has a low sensitivity to see the efficiency of the kidney. The serum creatinine will increase, only when the kidneys are already degenerative extremely. In addition, there are many factors that influence serum creatinine values, such as muscle mass, age of patient, protein content in the diet and so on.

Reference:

Saturday, August 15, 2015

Erythromycin and people with abdominal pain

Question: Erythromycin is contraindicated in persons with a history of severe muscle spasms. Is it yes or not?

Answer: Erythromycin is one drug of macrolide group (such as azithromycin, clarithromycin, roxithromycin, midecamycin, spiramycin, etc.).The data can be searched: erythromycin is not contraindicated for patients with a history of muscle spasms (especially skeletal muscle). However, there are reports of erythromycin increasing the contraction of smooth muscle, particularly in the gastrointestinal system. By acting through motilin receptor at the upper gastrointestinal tract that causes abdominal pain.

Thus, avoiding the use of macrolide group may be done in patients with a history of abdominal muscle contraction.

Reference:

Dig Dis Sci 1994; 39 (2): 381-4.

Friday, August 14, 2015

Drugs used to treat dogs and cats mostly similar to drugs used with people

Question: The drug which veterinarian (animal doctor) uses to treat the animal (cats, dogs) is the same type to treat people including antibiotic, antihistamine etc. Is it true or not?

Answer: Drugs are used to treat dogs and cats mostly similar to the drugs used with people. Including antibiotics and antihistamines (the dog’s wet nose is common, it is not like a cold or allergies).

But there are some medications that are the exception, such as paracetamol which will not be used as analgesic on dogs and cats because of toxicity. Especially toxic to cats, even 125 mg per dose may cause a cat to death.

Ibuprofen is very toxic to dogs, while phenylbutazone (for analgesic and inflammation) rather safes with dogs.

It is very important to consider dose of each drugs. Some medications are used in the dosage equal to people. However, some drugs are used very different doses.
Such as:- Amoxicillin; dose for common infections is 10 mg / kg by oral or injection 2-3 times per day, if the infection is severe, dose can up to 20 mg / kg 2-3 times per day.
             - Chlorpheniramine; dose for allergies and skin rashes of dog is 0.5-1 mg / kg, and cat 1-2 mg 2-3 times a day.


Which medication should not be chewed, broken or crushed before eating?

Question: Which medication should not be chewed, broken or crushed before eating?

Answer: There are five different types of drugs that should not be chewed, broken or crushed before eating.
(1)        Extended-Release product also include in the form of controlled-release, modified-release. Often be identified by CR, MR, XL or SR after the trade name of the drug, such as Adalat CR, Diamicron MR, Xatral XL, Isoptin SR, etc.
(2)        Enteric coated product, including medications that irritate the stomach or the intestines, such as aspirin.
(3)        Sugar coated product. Most drugs of this type have bad taste.
It must be coated by sugar to cover the flavor of medicine.
(4)        Sublingual product administered sublingually.
(5)        Effervescent product. If it is broken or crushed before dissolving in water, it may affect the capability of water solubility of the drug.

Reference:
Drug information handbook 10th anniversary edition, 2

Thursday, August 13, 2015

The amount of calcium in calcium salts

Question: Do you recommend me how to choose to eat calcium since there are many types of calcium?

Answer: Choosing to use calcium supplements generally depending on the type of calcium salts. The amount of calcium is contained in each type of calcium salts are not equal.

Any salt that contains much calcium will likely be absorbed into the body more than other salts. Calcium is absorbed more or less, also depending on the water solubility and disintegration of those salts.

Calcium salt                 Calcium (%)
Calcium glubionate           6.5
Calcium gluconate            9.3
Calcium lactate               13.0
Calcium citrate                21.0
Calcium acetate               25.0
Tricalcium phosphate       39.0
Calcium carbonate           40.0
Calcium chloride              27.3
Calcium gluceptate           8.2

Most salt found in products such as calcium carbonate, gluconate, citrate and lactate-gluconate and so on. Calcium salt is offered in various oral forms including calcium tablets, chewable and effervescent tablets of calcium.

In addition to consider the types of calcium salt, we also need to consider the amount of calcium obtained from the nutrients from the past to the present, exercise, and congenital disease especially those with renal disorders which should consult a physician before using calcium.

A lot of amount of calcium in the salt does not always work, it often cause constipation, frequently bloating such as carbonate salt, but this type of salt is cheaper compared to other types.

References:

Drug facts and comparisons pocket version, 7th edition, 2003.

Vitamin B-17 or laetrile

Question: What is vitamin B-17?

Answer: vitamin B-17 is another name of "laetrile", a substance found in plant especially seeds were used to make products for cancer treatment in some countries.
But it has not been tested the effectiveness of the treatment in cancer patients and has not been approved by the Food and Drug Administration of U.S.A.
Moreover, the research published in The New England Journal of Medicine in 1982 that laetrile is not effective in the treatment of cancer. And there is a danger of cyanide, which is released from that substance.

Vitamin B-17 is not essential vitamin to the human body in any way.

Refererences:

http://www.fda.gov/fdac/departs/2001/201_irs.html

Way to reduce side effects of tramadol.

Question: I want to know way to reduce the adverse effects of tramol (such as dizziness, nausea and vomiting), when a patient needs to use this drug.

Answer: Tramal® is the trade name of tramadol(=generic name), which is a group of opioids, tramadol is indicated for the relief of pain. The side effects that can be found are drowsiness, constipation, dry mouth, nausea, vomiting, confusion, dizziness, fatigue, itching, respiratory depression.
Drug is used in high doses causes more side effects. For drowsiness, nausea and vomiting that most patients can tolerate these symptoms, when using the drug for a while.

To remedy the adverse effects of tramadol, it is recommended that patients should avoid factors that stimulate symptoms. Such as; drinking alcohol, rapidly changing posture, some medicines and supplements such as calcium, antibiotics, muscle relaxation and so on.
However, do not recommend taking other medicines to reduce side effects from tramadol. If the patient is unable to tolerate side effects, it may be necessary to consider other types of pain relief medication.

References:
1. Ping NH, Lim C, Francisco JC, Pena LAD, Fajayan LJA, Solivet ZJN, et al. Mims Thailand. 133rd ed. Bangkok: MIMs (Thailand) Ltd; 2013.
2. McPherson ML. Strategies for the management of opioid-induced adverse effects. University of Tennessee Advanced Studies in Pharmacy 2008; 5 (2): 52-7.




Wednesday, August 12, 2015

Antidote of tramadol

Question: What is antidote of tramadol and how much dose used in children and adults?

Answer: Tramadol is a type of opioids used to relieve pain. The drug is used as an antidote of opioids is opioid antagonists.

However, tramadol overdose should be treated symptomatically. Such as: Treatment for the respiratory (resuscitation) and circulatory systems and prevention for seizures.


Opioid antagonist is used as an antidote is naloxone. However, the drug does not treat all the symptoms and the drug can cause seizures. The seizures can be controlled by diazepam.


.   Dosage of naloxone in children
Initial dose is 0.01 mg / kg by intravenous (IV bolus) then increase to 0.1 mg / kg, repeated every 2-3 minutes. Maximum dose is 2 Mg.
.   Dosage of naloxone in adults

IV bolus 0.4 to 2 mg, repeated every 2-3 minutes. Maximum dose is 10 mg.

If the patient could not be administered intravenously, can be considered for subcutaneous injection or intramuscular injection instead, and using the same dosage.

And if the patient has been administered to 10 mg of naloxone, but the symptoms did not improve. It may be needed to determine the cause of the symptoms once again that caused by overdose of tramadol or not.

Reference:
1. Wermeling DP. Review of naloxone safety for opioid overdose: practical considerations for new technology and expanded public access. Ther Adv Drug Saf 2015; 6 (1): 20-31.
2. Kastrup EK, Johnson PB, Meives CA, Willians AL, Moore LL, Bush AJ, et al. Drug Facts and Comparisons. St. Louis: Wolters Kluwer Health, 2012.
3. American Pharmacists Association. Drug Information Handbook with International Trade Names Index. 22th ed. Ohio: Lexi-Comp Inc, 2013.

Monday, August 10, 2015

Eritromax and Hemaplus (alpha erythropoietin)

Question: Eritromax can be used instead of Hemaplus or not.

Answer: Generic name of Eritromax® and Hemaplus® are similar; alpha erythropoietin. They are a type of biological drugs that contain glycosylated protein.
Each brand of drug has a different manufacturing process. Each drug affects each patient differently in terms of effectiveness and safety, especially the ability to producing an immune response (immunogenicity), and adverse reaction of drug is pure red cell aplasia (bone marrow does not build red blood cells permanently). This results in severe fatal of the patient.

Therefore, the use of alpha erythropoietin, not recommended changing brands of drug, because it affects the efficiency of treatment and affects the patient safety.


References:
1. Ping NH, Lim C, Francisco JC, Peria AL, Fajayan JL, Sollvet JZ, et al. Mims Thailand. 133rd ed. Bangkok, 2013.

2. Praditpornsilpa K, Tiranathanagul K, Kupatawintu P, Jootar S, Intragumtornchai T, Tungsanga K, et al. Bio¬similar recombinant human erythropoietin induces the production of neutralizing antibodies. Kidney Int 2011; 80 (1): 88-92.

Sunday, August 9, 2015

Pain at the injection area of diclofenac.

Question: Patients have pain at the injection site of the drug diclofenac. Can we mix diclofenac injections with injections of lidocaine or not? Or has any other better way to make specific area injected less painful?

Answer: The symptoms of pain at the injection site of diclofenac can occur more than 1%. Mixing drugs lidocaine and diclofenac by yourself is not recommended.

Mixing the two drugs together by ourselves may be a problem, because each drug may contain other substances and both drugs may not mix well.

However, it can relieve pain at the injection site by gently massaging the injection site after injection of diclofenac.


Currently there is a combination between lidocaine and diclofenac in the dosage form of intramuscular injections on the market; such as voltaren injection etc.

References:
1. NHS choice. Diclofenac injection. Available from:http://www.nhs.uk/conditions/arthritis/pages/MedicineSideEffects.aspx?condition=Pain&medicine=diclofenac%20sodium&preparation=Diclofenac%2075mg/3ml%20solution%20for%20injection%20ampoules
2. Diclofenac. IV compatability. Micromedex 2.0. Truven Health Analytics, Inc. Greenwood Village, CO. Available from: http://www.micromedexsolutions.com.
3. Kanika KH, Rani SP. Effect of massage on pain perception after administration of.

intramuscular Injection among adult patients. Nurs and Midwife Res J 2011; 7: 130-8.

Aspirin in the form of enteric coated tablet

Question:
Aspirin in the form of enteric-coated tablet disintegrates in the small intestine not the stomach, but it also is recommended eating immediately after meals, and drinking more water to prevent stomach irritation. What is the reason?

Answer:
Aspirin (aspirin) in a film coated tablet  (enteric-coated) made with the purpose of  reducing abdominal discomfort caused by the drug directly exposed stomach which can cause irritation to the stomach.

However, the symptoms of stomach irritation and increased risks of bleeding in the gastrointestinal tract is also a pharmacologic effect of aspirin. (Aspirin reduce the synthesis of prostaglandins which protects the stomach wall and inhibit acid secretion.)

Thus, all dosage forms of aspirin including enteric coated tablet may increase the risk of bleeding in the stomach. Therefore it need to be eaten immediately after a meal and drinking more water.

References:
1. Tatro DS. A to Z Drug Facts. 8th ed. Missouri: Wolters Kluwer Health, 2007.

2. Weitz JI. Blood coagulation and anticoagulant, fibrinolytic, and antiplatelet drugs. In: Brunton L, Chabner B, Knollman B. editors. Goodman & Gilman's the Pharmacological Basis of therapeutics. 12th ed. New York: McGraw-Hill, 2011; p868.

Ibuprofen and adverse reactions.



Question: Ibuprofen is NSAIDs with the lowest risk for GI bleeding, is it true or not?

Answer:
NSAIDs (or non-steroidal anti-inflammatory drugs), which usually mean the conventional NSAIDs or non-selective NSAIDs that inhibit prostaglandin by inhibiting cyclooxygenase enzyme (COX), both COX-1 and COX-2.

Drugs in this group have pain relief, can reduce fever and reduce inflammation. So they usually used to relieve pain and reduce inflammation in arthritis and more.

Inhibiting COX-1 cause irritation in the stomach and cause bleeding in the digestive tract, so adverse drug reaction is gastro-intestinal bleeding (GI bleeding)

The adverse reactions occurred more or less is based on the type of drugs that affect COX-1 more or less.
It also depends on the dose and age of the patient.
The adverse reactions occurred more or less is based on the type of drugs that affect COX-1 more or less. It also depends on the dose and age of the patient. (elderly often have more adverse drug reaction).

NSAIDs not only cause adverse reactions on the stomach but  also affect  the intestine.
Non-selective NSAIDs (such as Ibuprofen, diclofenac, naproxen, indomethacin and piroxicam) and the risk of GI bleeding, compared with the paracetamol.


From the above image.

Ibuprofen 1200 mg / day had the lowest risk of GI bleeding, compared with paracetamol. But ibuprofen ≥1,200 mg / will has the risk of GI bleeding more than paracetamol.

The other drugs mentioned above, even in low doses, namely diclofenac <75 mg / day, indomethacin ≤50 mg / day, naproxen <500 mg / day and piroxicam ≤10 mg / day. These increase the risk of GI bleeding a lot, especially piroxicam (see image).

References:

(1) Moore N, Pollack C, Butkerait P. Adverse drug reactions and drug-drug interactions with over-the-counter NSAIDs. Ther Clin Risk Manag 2015; 11: 1061-75; (2) Scarpignato C, Lanas A, Blandizzi C, Lems WF, Hermann M, Hunt RH, et al. Safe prescribing of non-steroidal anti-inflammatory drugs in patients with osteoarthritis - an expert consensus addressing benefits as well as gastrointestinal and cardiovascular risks. BMC Med 2015; 13: 55. doi: 10.1186 / s12916-015-0285-8.