Massage & Bodywork

JULY | AUGUST 2021

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34 m a s s a g e & b o d y wo r k j u l y/a u g u s t 2 0 2 1 Injection sites are local contraindications for massage for a few hours at least. In the case of botulinum toxin (Botox), which is injected into the subdermis or intramuscularly, many physicians recommend waiting a few days before doing massage in that area. EXCRETION Most drugs are excreted through urine and feces, which typically happens within 48 hours of taking the dose. Some drugs, notably some types of chemotherapy, are excreted in sweat and sebum. MTs who specialize in working with cancer patients will need to know the protocols for clients who are dealing with this situation—that is an issue to discuss with their health-care team. PHARMACODYNAMICS (PD) Pharmacodynamics refers to the action of the drug: what it does to its target cells and tissues. Medications use many strategies to achieve the goals of treatment, and more are in development all the time. Here are some of the most common pharmacodynamics, with examples of drugs that work in this way: Cell membranes. Some drugs may act on cell membranes to limit or promote the passage of substances into or out of the cell. For example, metformin (Glucophage) makes cells more receptive to sugar. Body fluids. Medications may alter the chemical properties of some fluids. For example, proton pump inhibitors (Prilosec, Prevacid) change the pH of stomach secretions. Enzyme systems. Some drugs change the enzyme systems inside or outside cells. For example, selective serotonin reuptake inhibitors (Prozac, Zoloft, Paxil) alter the activity of enzymes that By Mouth Most common medications are taken orally (or "per os"— by mouth). This is easy and convenient for many patients, but the substance has to undergo filtration and metabolism in the liver before it enters the general bloodstream. Whatever makes it that far is called the bioavailable fraction of the drug. This means a person's digestive and liver function may influence how much of a medication they need to receive any benefit. Some drugs cannot withstand this process, and they degenerate before they are usable; this is why insulin cannot be taken orally. Because massage seems to boost digestive motility, our work may have an impact here. Topical Application In this context, we are referring to medications that are intended to enter the bloodstream, rather than substances like pain-relieving gels or creams that are meant for local impact only. In order to access the blood via the skin, drugs must be administered in high concentration, have duration of contact with an area of skin with hair shafts, and be soluble with a molecular weight that allows it to pass into the capillaries. Sometimes these medications are used with solvents to help carry them across the epidermis and into circulatory or lymphatic capillaries. Topical applications have some advantages over orally taken doses of medications: They bypass the filtration of the liver for direct access to the bloodstream and lymphatic system, and they can be applied in multiple locations to avoid irritation. From the point of view of massage therapists, however, topical applications of medications may carry some risks. If the dose is in the form of a patch, like nicotine or birth control patches, it is easy to identify and avoid (I suggest avoidance of several inches in every direction, because we don't want to change the rate of uptake at the site). But some topical medications, especially hormone creams, may not have any visible signs. More than one massage therapist has asked me whether they were inadvertently dosed when working with clients who didn't tell them about their estrogen or testosterone cream until after they had already touched the area. Fortunately, the palms of the hands are among the least permeable parts of the body, and if our skin is intact—and we wash our hands frequently—our risk of significant exposure to medications in this way is minimal. Still, if we know our client has used a hormone cream or other topical application of a drug in some area, it is best to avoid it, so we don't have unintended influence on the dosage or uptake. Through Mucous Membranes Some medications are inhaled, absorbed through the mucous membranes of the cheek or under the tongue, or absorbed as suppositories in the rectum or vagina. Like topically applied medications, this avoids filtration by the liver, giving almost instantaneous access of the drug to the circulatory system. Nitroglycerin sublingual tablets (Nitrostat) for chest pain are an example of this kind of fast action. One of the challenges with drugs given by way of mucous membranes is that the uptake can be variable and unpredictable. This is why inhaled insulin didn't work for most people: It is a drug that has to be given in the right dosage, at the right time, and this was too hard to predict when it was used as an inhalant. By Injection Injections of medications can happen in a few ways. Drugs can be pushed into the subcutaneous space (insulin is an example) or into the intramuscular space, like vaccines or antibiotics. In some situations, it is best for a drug to access the bloodstream immediately. This is done with an intravenous (IV ) application. If this is an ongoing need, a patient may have a port or a peripherally inserted central catheter, or PICC line.

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