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Clinically, the same drug takes different routes of administration. Why do you use different doses? ..
Choose reasonable drugs for different therapeutic purposes. The factors of relative dosage form are complex, involving medicinal chemistry, physical chemistry, pharmacy, biopharmaceutics and other disciplines. Clinicians and nurses have insufficient pharmaceutical background. At present, there are many problems related to drug dosage forms in clinical medication, and medical institutions lack sufficient attention to the relationship between dosage forms and rational drug use. dosage

Type A factor has become a "blind spot" in hospital pharmacy and clinical pharmacy research. 1

Rational dosage form and administration of drugs

The choice of administration route is an important factor to ensure and improve the curative effect of drugs. This paper analyzes the rational application of new dosage forms in the current route of administration. ?

What are the basic principles for choosing 1 route of administration? Select 1. 1 according to the needs of clinical treatment. ?

There are many kinds of clinical diseases. In order to adapt to the nature, treatment methods, patients' age and disease state, according to the types and characteristics of diseases, the appropriate route of administration and corresponding dosage forms are determined. For example, patients with severe heart and lung diseases and renal insufficiency should not be given intravenous drip to avoid increasing the burden on the heart and lungs. When it needs to be used, the liquid medicine should be made into small drops, and the dropping speed should be slow. At the same time, we should closely observe the heart, lung and renal function. ?

Infants have poor swallowing ability, and intramuscular injection will affect drug absorption due to insufficient local blood circulation, so it is often used for intravenous drip in the elderly, infants, emergency patients and coma patients. In order to better play or increase the curative effect of drugs, accelerate or delay the action of drugs, and increase the targeting of drugs to certain systems, the retention of target tissues, the permeability of tissues and cells, etc. Suitable excipients and new technologies can be selected to prepare new dosage forms. ?

The concentration of antiviral drug ribavirin in respiratory secretions is mostly higher than that in blood. When used for viral pneumonia and bronchitis caused by respiratory syncytial virus, considering the incidence of adverse reactions of this drug, a better choice is atomized inhalation. It must be used in strict accordance with the aerosol generator and administration method described in the administration instructions. ?

For example, in the choice of nitroglycerin, the drug film takes effect three times faster than tablets in vivo; Some drugs are absorbed slowly and incompletely after intramuscular injection, such as diazepam, phenytoin sodium, digoxin and quinidine, which are not better than oral administration. ?

1.2 according to the physical and chemical properties and biological characteristics of drugs.

The physical and chemical properties of drugs provide a basis for the application and compatibility of pharmaceutical excipients in the preparation of dosage forms. Pharmaceutical excipients can be dissolved, suspended, thickened, diluted, emulsified, stabilized, protected, colored, flavored or modified to form effective and suitable pharmaceutical preparations. According to biopharmaceutics, the distribution of drugs is closely related to the curative effect, as well as the accumulation and side effects of drugs in tissues. Such as bioadhesive administration

System (bioadhesive? Drugs? Delivery? System, BDDS) is a new branch of modern dosage forms, which can be divided into oral adhesive preparation, nasal adhesive preparation, gastrointestinal oral adhesive preparation, ophthalmic adhesive preparation, hysterovaginal adhesive preparation, rectal adhesive preparation and so on according to different parts of human tissues.

form of a drug

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Different routes of administration can affect the amount and speed of drug absorption, and the absorption speed is as follows: intravenous

Injection-inhalation injection-intramuscular injection-subcutaneous injection-rectal mucosa-oral administration-skin. three

1.3 according to the safety of clinical medication?

Oral administration is a safe, convenient and economical medication method, and it is also the most commonly used method. Oral drug

After absorption, it can be absorbed through the gastrointestinal tract and act on the whole body, or it can stay in the gastrointestinal tract and act on the gastrointestinal part. However, it should not be used in the following situations: ① The patient is unconscious or unable to swallow; 2 because of gastrointestinal diseases, it can't be absorbed; (3) Due to the nature of the drug itself, it is not easy to be absorbed by the gastrointestinal tract or can be destroyed by the acidity and alkalinity of the gastrointestinal tract and enzymes (such as insulin and penicillin); (4) Oral administration can not achieve the specific effect of the drug (for example, oral magnesium sulfate can only play a purgative role, and it must be injected if it is necessary to play a sedative role). In all these cases, other methods of administration must be used.

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Oral syrup is suitable for infants; Chewable tablets are suitable for children over one year old, and the dosage of chewable tablets is accurate.

Indeed, it is conducive to absorption; Children can also choose granules, drops, powders, capsules and suspensions, and shake them well before use. ?

1.4 Selection according to patients' medication compliance

The compliance of drug treatment refers to the degree of compliance of patients with the application of drugs prescribed by doctors, and it is also an important guarantee for the drug to exert its curative effect. Poor compliance will lead to rapid disease deterioration and even death, and will also increase medical costs. It is reported that once a day, the compliance rate is 75%, and two, three and four times a day, the compliance rates are 70%, 52% and 42% respectively. According to the course of treatment, three days is a course of treatment, and the compliance rate is 5 1%.

Six days and seven days are a course of treatment, and the compliance is 30% and 20% respectively. 5?

The taste of drugs, complicated treatment scheme and usage, variety and frequency of drugs, curative effect and adverse drug reactions also affect the treatment compliance. However, long-acting sustained-release dosage forms, effervescent tablets, dispersible tablets and orally disintegrating tablets are convenient for the elderly and children to use and can improve compliance. Topical use of transdermal drug delivery preparations (TDDS) has systemic effects and good clinical compliance. Non-injection drug delivery system is beneficial to improve the compliance of patients. Non-injection routes include nasal, oral, rectal, oral, transdermal and pulmonary administration, but oral administration is the most popular route. ?

2 the correct use of commonly used drug dosage forms? The dosage forms of drugs have their own characteristics, and the correct use is related to the curative effect of drugs.

Therefore, when selecting and using pharmaceutical dosage forms, we should understand the characteristics of pharmaceutical dosage forms. ?

2. 1 gastrointestinal dosage form refers to the dosage form in which a pharmaceutical preparation enters the gastrointestinal tract after oral administration and plays a local or systemic role after absorption. ? 2. 1. 1 cannot be crushed, but must be chewed?

The appearance of sustained-release tablets is similar to that of ordinary tablets, but the tablets are covered with a semi-permeable membrane. After oral administration, gastric juice can enter the tablet through the semi-permeable membrane to dissolve some drugs, forming a certain osmotic pressure, so that the saturated drug solution passes through the micropores on the membrane and is slowly discharged at a non-constant speed in a certain period of time. After the drug is released, the shell is discharged from the body. Controlled-release tablets refer to putting drugs into a synthetic high-quality inert polymer. After oral administration, the drug is released at a slow or nearly constant rate as needed. When the drug is released, the polymer is dissolved and excreted. Do not crush it when taking it, otherwise it will affect the curative effect of the drug, cause irritation, and cause nausea and vomiting. Or lose enteric or controlled release effect. ?

Controlled-release tablets can be divided into two types, such as ibuprofen sustained-release capsules, which are composed of a certain proportion of non-isokinetic drug particles (distinguished by different colors), so that the drug can be released intermittently, thus maintaining the effective concentration for a long time. If the drug is poured out of the capsule, it is difficult to ensure the original proportion of the drug, which will inevitably affect the sustained release effect of the drug. ?

Sustained-release pellets can be taken separately according to the required dosage. For example, metoprolol sustained-release tablets adopt a multi-unit microcapsule system consisting of hundreds to thousands of spherical microcapsules with a diameter of about 0.5㎜ or less, and each microcapsule is an independent constant-speed release unit. Sustained-release pellets are also made of abidol hydrochloride, sinomenine hydrochloride and ofloxacin. In application, attention should be paid to whether particles are prepared. ?

Some tablets, such as compound weishuping, aluminum hydroxide tablets and colloidal bismuth subcitrate tablets, must be chewed according to their effects on diseases. After they are chewed, they enter the stomach and quickly form a protective film on the stomach wall, thus reducing the irritation of stomach contents to gastric ulcer. When angina occurs in patients with coronary heart disease, nitroglycerin tablets can be chewed up and placed under the tongue to quickly relieve angina symptoms. When the blood pressure of hypertensive patients suddenly rises [diastolic blood pressure is above 13.33 kPa( 100 mmHg), taking a nifedipine tablet immediately and chewing it under the tongue can play a role in rapidly lowering blood pressure, thus avoiding the possible danger caused by hypertension. In addition, some drugs are in the form of chewable tablets (montelukast chewable tablets, aluminum-magnesium chewable tablets, cimetidine chewable tablets? Cetirizine hydrochloride chewable tablets), more.

It needs to be chewed and ground carefully to play a role. 6?

2. 1.2 Does it need water or water?

No need for water orally disintegrating tablets: it can be quickly dissolved in the mouth when it meets saliva, and it is convenient to take. special

Suitable for children, people with dysphagia and the elderly who stay in bed for a long time. At present, erythromycin ethylsuccinate orally disintegrating tablets and acetaminophen orally disintegrating tablets are commonly used in clinic. ?

Need to take it with water: ① Dispersible tablet is a quick-acting preparation, which can quickly disintegrate into a uniform suspension in water, with convenient administration, quick absorption and high bioavailability. Is there amoxicillin dispersible tablet in clinic? Cefradine dispersible tablets? Xuesaitong dispersible tablets. ? ② Effervescent tablet: It is characterized by generating a large number of bubbles when it meets water, and quickly dissolving into clear liquid, which is convenient to take, delicious in taste, accurate in dosage and good in absorption. Suitable for children, the elderly and people who are not easy to swallow drugs. Commonly used in clinic are vitamin C effervescent tablets, tinidazole vaginal effervescent tablets and aspirin effervescent tablets. ③ gastric retention sustained-release tablets (stomach? Relax.-Floating? Tablet) is a kind of sustained-release preparation that can float on gastric juice after oral administration, and its retention time in the stomach is as long as 7 ~ 8 hours, but it needs considerable gastric juice to make the preparation float and play a therapeutic role. Taking 200 ~ 250 ml of water at the same time can increase the amount of gastric juice. Ciprofloxacin and Angelica polysaccharide iron floating sustained-release tablets are commonly used drugs in clinic.

2.2 Non-gastrointestinal administration type?

2.2. 1 injection type: intravenous administration often meets the problem of dilution concentration, such as vinpocetine injection must be diluted to 0.06mg/ml when intravenous drip, otherwise hemolysis may occur; Clindamycin must be diluted to 0.6 mg/ml by intravenous drip; Ganciclovir 10mg intravenous drip needs 500? The final concentration of azithromycin injection by intravenous drip is 1.0 ~ 2.0 mg/ml. Another thing that is easily overlooked is the influence of containers on things. For example, do not use polyvinyl chloride (PVC) plastic containers when injecting nitroglycerin intravenously, because nitroglycerin can be adsorbed on PVC. ?

2.2.2 Respiratory tract dosage forms: The new dosage forms used for pulmonary administration include inhaled nanoparticles, porous nanoparticles aggregated particles, microspheres, porous particles and liposomes, which can prolong the action time of drugs, reduce the times of taking drugs and improve the compliance of patients. The dosage forms of inhaled drugs mainly include metered pressure aerosol (metered? Dose? Inhaler, MDI) and dry powder inhaler (dry? Power? Inhalation, DPI), whose representative drugs are budesonide powder inhalation and salmeterol fluticasone powder inhalation respectively. It is worth noting that professional and technical personnel should guide patients to master the use method correctly to avoid drug failure or drug waste. Is budesonide formoterol powder inhalation commonly used in clinic?

2.2.3 Transdermal drug delivery system (TDDSs) can promote therapeutic drugs to enter the systemic circulation through the skin and play a systematic role. The ideal transdermal drug delivery system is that drugs can enter the blood without accumulating under the skin after penetrating into the skin. The selected parts should be recommended in the manual, which is out of scope.

Rotate in the same position to ensure normal permeability and avoid irritating the skin every time. TDDSs is suitable for clean and dry skin, with little hair loss, no greasy, no irritation, no inflammation, no scratches and no knots.

Hard block parts. TDDSs cannot be reduced (if the dosage needs to be reduced) because it will destroy the integrity of the system.

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According to the special usage of clinical experience, potassium chloride injection can supplement potassium orally, lincomycin eye drops and nasal drops can diminish inflammation, and smecta, an antidiarrheal drug, can be directly applied to the mouth to treat oral ulcers. Periodontal diseases can be treated with various dosage forms. The main method is to put the drug preparation directly in the periodontal area, so that it can be released directly in the patient's site. At present, there are mainly tetracycline fiber (Actisite), doxycycline gel injection (Atridox), minocycline ointment injection, minocycline microsphere injection (Arestin), metronidazole gel injection (Elyzol) and metronidazole stick (Yakang). Periodontal treatment also includes mouthwash, rinse and film coating. ?

With the rapid development of medical science, there are more and more kinds of clinical drugs, but in some aspects, the level of clinical drug treatment has not been greatly improved with the increase of drug varieties. Patient-centered, medical cooperation, strengthening the management of all aspects of drug use, assisting clinical rational drug use, and further improving the level of rational drug use in hospitals. Therefore, knowing the dosage form and route of administration can make a reasonable administration plan, improve the level of clinical medication and promote safe and rational medication. ?

References:?

[1] Ding Yufeng? On the factors of clinical dosage forms and rational drug use (j) Medical guidelines? 2007? 26(5):447-450? [2] Liu Na? Lin Huaqing? The latest development of new dosage forms of bioadhesive drug delivery? China Pharmacist (J)2007, (10)1:1133 ~134?

[3] Editorial Committee of National Formulary of Essential Drugs? National Formulary of Essential Drugs (M), Beijing; People's Health Publishing House, 2009: 6?

[4] China Licensed Pharmacists Association? Textbook of Continuing Education for Licensed Pharmacists in China (J) Beijing: China Traditional Chinese Medicine Press, 2006,92?

[5] Li Tianyuan? Talking about children's rational drug use? Drug and Clinical Research (J)? 2007, 15( 1):? 63~64? China Licensed Pharmacists Association? Textbook of Continuing Education for Licensed Pharmacists in China (J) Beijing: China Traditional Chinese Medicine Press, 2006,95?

[7] (America) Ansel, (America) Allen (America) Popovich, Jiang Zhiqiang translated "Drug dosage forms and drug delivery systems" (M), Beijing; China Medical Science and Technology Press, 2003: 289 ~ 300?

[8]? Zhao Yanlong? Bao Yongchu? Chen Qinghua? Progress in clinical application of topical drugs for periodontal diseases and their new preparations (J)? World clinical drugs? 2009? 30(6)? 370—373? 2?