Understanding and correction of common mistakes in clinical medication of canine diseases

Because the doctors' understanding of the treated animals, the understanding of the disease and the effect of the drugs are unknown, various mistakes will occur in the process of drug use. Although this kind of mistake will cause the failure of treatment and even produce toxic reaction, it can also provide the basis for correct diagnosis and implementation of drug therapy for future diseases. Therefore, the understanding and correction of clinical medication errors is a positive practice in veterinary clinic.

1 the common types of medication errors

The types of clinical medication errors include diagnostic errors, drug selection errors, compatibility errors, dose errors, usage and dispensing errors and so on. The consequences are reduced efficacy, adverse reactions, poisoning or death, causing drug-induced diseases and increasing the cost of treatment. For example, ① gives sulfonamides to sick dogs that have been given procaine, and the antibacterial effect of sulfonamides is antagonized; ② injects penicillin potassium or sodium salt to treat bacterial diarrhea in animals, but the antibacterial spectrum of the drug is wrong and the effect is not good; ③ uses thio-dichlorophenol (paracetamol) or agents containing paracetamol to adult dogs or young dogs, causing excessive dose, mild diarrhea and other symptoms, and severe causes enteritis, dehydration and heart failure. When magnesium sulfate was injected intravenously into dogs by ④, the respiratory center was paralyzed to death due to excessive speed (not too much dose). Cardiotonic agents such as ⑤ sodium coffee or digitalis glycoside were mistakenly injected with calcium at the same time (including separate or successive administration), because calcium ion could weaken the excitability of myocardium and lead to cardiac arrest. ⑥ chlorpromazine combined with analgin caused a sharp drop in body temperature, and excessive dose could lead to animal failure. Long-term use of aminopyrine, analgin or chloramphenicol in ⑦ causes granulocytopenia; ⑧ trichlorfon in combination with alkaline drugs such as sodium bicarbonate or containing sodium bicarbonate (such as artificial salt) can turn into highly toxic dichlorvos and cause poisoning; ⑨ tetracycline and prednisone can cause digestive disorders or gastrointestinal bacterial "double infection" diseases in dogs.

2 mistakes due to improper drug selection

This is particularly common when using antimicrobials. At present, the commonly used clinical antimicrobials are antibiotics, polyether feed antibiotics, sulfonamides and their synergists, furazolidone, quinolinol and quinolones (norfloxacin, enrofloxacin, ciprofloxacin, etc.).

2.1 mistakes in the selection of antibiotics

2.1.1 abuse of penicillin potassium or sodium salt. Penicillin is cheap and has a good anti-infective effect, except for occasional allergic reactions, there are generally no toxic side effects, so there is often abuse. In fact, it is mainly suitable for diseases infected by Gram-positive bacteria, such as pneumonia, endometritis, mastitis and traumatic infection and a few Gram-negative bacteria.

2.1.2 use new and expensive antibiotics as routine drugs. For example, cephalosporin (cephalosporin) can be used in the treatment of acute and severe infections or cases of drug resistance or valuable pets that are ineffective by other antimicrobials, and the Ministry of Agriculture has recently banned the transplantation of such drugs from human medicine to the veterinary field.

2.1.3 misled by advertising, there is a lack of understanding of the adverse reactions of some newly used drugs in China. For example, norfloxacin, enrofloxacin and ciprofloxacin in quinolones have the advantages of wide antibacterial spectrum, low antibacterial concentration and no cross-resistance in this kind of drugs. However, this kind of drug has been used abroad for 30 years, and it has not only drug resistance and adverse reactions of digestive tract and nervous system (vomiting, abdominal pain, nervous symptoms in cats and dogs), but also can damage the cartilage development of young animals and cause claudication. Crystallization damage kidney is easy to be formed in acid urine of carnivores, and these reactions are aggravated with the increase of dose.

2.1.4 ignore the normal use of some cheap and effective agents. For example, furazolidone and some compound sulfonamides, such as SD+TMP, compound sulfadiazine sodium, SMZ+TMP synergist, sulfamethoxazole, etc.

2.2 suggestions on the selection of antimicrobials and insect repellents

2.2.1 antimicrobials can be divided into Ⅲ categories: Ⅰ commonly used antimicrobial agents, penicillin potassium or sodium salt (main anti-Gram-positive bacteria), ampicillin (anti-Gram-positive and Gram-negative bacteria), gentamicin (anti-Gram-positive and Gram-negative antibiotics that are ineffective to penicillin) Ⅱ special antimicrobial agents, such as chloramphenicol (anti-intestinal gram-negative bacteria), veterinary kanamycin, erythromycin thiocyanate, enrofloxacin (for bacterial infections with low efficacy of common antibiotics), etc. Ⅲ prophylactic antimicrobials such as olaquindox, oxytetracycline (all used as antimicrobial growth promoters), tylosin (antimicrobial, anti-mycoplasma and Leptospira growth promoters), diclazuril (new, highly effective, low-dose, drug-free anticoccidial agents).

2.2.2 strict order of drug use. Generally according to the first use of summer class (any one or two combination), the curative effect is not good, then use Ⅱ class (or in case of special illness), use class Ⅲ as feed additive in the same order.

2.2.3 adhere to reasonable course of treatment. If any kind of antimicrobials are used for 2 or 3 times, if the symptoms are not significantly improved, they should be changed to other drugs in time; if they are effective, they should be maintained for a course of treatment (usually 2 ~ 3 days).

3 errors caused by dose factors

3.1 the dose of antimicrobials increases with the use of them.

Or because of being harmed by fake or inferior drugs or misled by some rumors, some antibiotics (such as penicillin, ampicillin, gentamicin) are used more and more clinically, so that they are overused for a long time.

3.2 No reduction in the combination of antimicrobials

For example, when penicillin is used in combination with streptomycin, both drugs can be appropriately reduced (at least 1 stroke 3).

3.3 insufficient dose and course of treatment

For example, sulfonamides are required to be calculated according to body weight, the first dose should be doubled, and the maintenance dose should be maintained during the course of treatment (2 ~ 3 days). However, the clinical use of insufficient dose (especially the first dose is insufficient) and can not adhere to the maintenance dose or insufficient course of treatment.

3.4 Drug metrology errors

The dosage of solid drugs is usually calculated in grams (g), milligrams (mg) and micrograms (μ g), such as furazolidone. The daily dose of furazolidone is 5mg / kg body weight, which can be taken twice. Furazolidone tablets contain 0.1 grams (100 mg) per tablet. Take 5 kg puppies as an example, the daily dosage is 25 mg = 1 beat 4 tablets, twice a day, each time is 12.5 mg. If the measurement is wrong, it is easy to cause poisoning.

3.5 how to use the drug dose correctly

The dosage of the drug is different from the legal dose and the clinical experience dose. The legal dose is according to the records of Chinese Veterinary Pharmacopoeia and Veterinary Drug Code. The dose commonly used by clinical veterinarians is the empirical dose. The latter should be flexibly mastered on the basis of the former, although it can be brought into full play clinically, but it should be safe and effective. Some drugs have strict dose requirements and should be used according to the legal dose, such as some antibiotics with toxic side effects (such as streptomycin, chloramphenicol, doxycycline, etc.), sulfonamides, anesthetics (such as chloral hydrate, barbiturates), drugs acting on receptors (such as pilocarpine, atropine, epinephrine, etc.), antiparasitic drugs (such as trichlorfon, albendazole, etc.) Levimidazole, nitrochlorophenol, triazamidine, diclazuril, etc.), hormones (such as chorionic gonadotropin, oxytocin, prednisone, dexamethasone), vaccine and serum, etc. Anesthetics, antiparasitic drugs, antidotes, etc., should be measured strictly according to body weight. Olaquindox, diclazuril (anti-coccidiosis agent), etc., should be added to the feed by strict concentration measurement.

4 mistakes in the combined use of drugs

Because of the wide variety of veterinary drugs and the complexity of combined use of veterinary drugs, we only take antimicrobial agents as an example to illustrate.

4.1 agents that combine antagonism or reduce the efficacy of antimicrobials

① procaine containing PABA (p-aminobenzoic acid) can antagonize the antibacterial activity of sulfonamides; ② antibacterial antibiotics such as erythromycin and chloramphenicol can resist the antibacterial activity of penicillin; when ③ penicillin is combined with sulfonamides, the clinical efficacy of both decreases. Sulfonamides injection is strongly alkaline, and mixed injection with penicillin can destroy the antibacterial activity of penicillin. ④ sodium bicarbonate combined with oxytetracycline and tetracycline can reduce the gastrointestinal absorption of the latter two by 50% and reduce the efficacy; the injection of ⑤ vitamin B1, vitamin B2 and vitamin C has varying degrees of inactivation effect on ampicillin, cephalosporin Ⅰ and Ⅱ, oxytetracycline, chloramphenicol, doxycycline, streptomycin, kanamycin, lincomycin, etc., that is, antibiotics lose antibacterial activity, so they can not be mixed injected.

4.2 use of highly toxic antimicrobials

① dihydrostreptomycin itself has a strong ototoxicity, and ② streptomycin, kanamycin and muscle relaxants (such as succinylcholine) can aggravate neuromuscular paralysis and inhibit respiratory toxicity.

5 mistakes caused by the special toxic reaction of unknown drugs to animals

① dogs and cats (including tigers, lions, leopards) have special toxic reactions to phenols or phenolic agents containing phenols (such as phenol, cresol, compound phenols, paracetamol, etc.), and there have been reports of cats and tigers dying from poisoning caused by phenols; some ② dogs can cause poisoning with the effective deworming dose of trichlorfon, so be careful when using it.

6 mistakes caused by improper dispensing and usage of drugs

Take the dog feed premix as an example: such as furazolidone and quinolinol are agents with certain toxic and side effects; the dosage of sodium selenite and diclazuril is very small, and the addition amount per kg feed is only 0.31 mg and 0.1 mg respectively. When these drugs are mixed into the feed, if they are not first made into a qualified premixture, or if the "equal volume step-by-step dilution method" is not used when adding the feed, the dogs will be poisoned due to the uneven mixing. In addition, when the above-mentioned drugs are made into water-drinking agents, they are often prone to precipitation due to improper blending or the absence of cosolvents or suspensions, resulting in uneven consumption of drugs in animals, resulting in poisoning.