Unexpected Responses

Allergic Response

Some people develop allergic reactions to a specific drug. An allergic reaction is a hypersensitivity of the immune system to a foreign chemical in the body; in this case, a medication. A resident can develop an allergy to a drug at any time. Allergies may develop several days after starting a medication, even after repeated, uneventful uses of the medication. An allergic reaction is more likely to develop in people with other known allergies. This means even if the resident has taken a medicine before, he or she may still have an allergic reaction to it.

A mild allergic reaction may include symptoms such as fever, skin rash, or swelling of the hands, feet or around the eyes. A more severe allergic reaction is also possible. Anaphylactic shock is a life-threatening allergic response. A person with an anaphylactic reaction may experience hives, swelling, difficulty breathing, low blood pressure and/or a fast heart rate. Emergency medical treatment is required. An anaphylactic reaction may lead to respiratory and cardiac arrest. If you suspect a resident is having an allergic reaction, report it immediately to the person providing direction and monitoring.

Adverse Reactions

Adverse reactions are undesirable symptoms that occur because of a medication. Nausea, vomiting and diarrhea are not allergic reactions; they are adverse reactions. An adverse reaction to a medication can prevent the desired outcome or the body’s ability to use the medication. Adverse reactions can be severe and life-threatening. If a person has a history of allergies or adverse reactions, this information should be clearly identified so that problematic medications can be avoided. Teratogenic effects cause harm to a fetus. Certain medications should be avoided during pregnancy. Drugs should never be handled without gloves if contact is likely.


Some residents may become tolerant to the effects of certain drugs, particularly pain medications and sleeping aids. This is not the same thing as drug addiction or dependence. Some drugs, when given over a long period, must be given in progressively larger doses in order to be effective. The body builds up a tolerance to the chemical. Pain medication sometimes results in drug tolerance if given over a long period of time. Treating chronic pain correctly means occasionally adjusting the resident’s dose in order to keep him or her comfortable. The resident is not addicted to the drug because if the pain goes away, the drug can be stopped without symptoms of withdrawal. Do not be afraid to give pain medication according to the physician’s instructions, even if the dose seems higher than usual and particularly if the resident has already been on pain medication for a period of time.


Drug dependence occurs when a person experiences withdrawal symptoms when the drug is discontinued. Symptoms can include irritability, tremors, confusion, sweating, hallucinations, nausea, vomiting or anxiety. The person may also experience emotional or physical changes. Medications to which a resident has developed dependence should be withdrawn very slowly. Careful monitoring should take place between the person providing direction and monitoring and the physician.

Effects of age

The effects of medication can change across the lifespan. Very young and very old individuals may exhibit great variations in absorption, distribution, metabolism and elimination. In a child, the low amount of acid in the stomach may prevent a medication from dissolving completely. The proportion of water to other body tissue is higher in a child’s body than in an adult’s. This water proportion can affect how a drug moves around in the body. How the body uses a drug is more unpredictable in children than in adults because children’s metabolic rates can differ greatly. The age of the kidneys can also affect how well a drug is excreted. Children often react more rapidly and in unexpected ways.

Advancing age can also affect how drugs are used in the body. Medications may not dissolve well in the older adult’s stomach because of low acid content. Blood circulation may be slowed, decreasing the absorption of medications through the intestinal wall. Medications also may not be well absorbed into other body tissues. Older blood vessels have walls that are tough and coated with fatty deposits, which may make distribution difficult.

The older person’s liver may not metabolize drugs as well, which can result in high levels of the medication remaining in the bloodstream. Also, the older person’s kidneys may not filter drugs efficiently from the blood. Because the body of the older person does not absorb, metabolize or excrete drugs well, some drug levels in the bloodstream are measured on a regular basis. Drug levels are obtained to be sure the resident is getting the right amount of medication.


Polypharmacy means “many drugs.” It can be a major problem for older people. Some residents have many different chronic illnesses. Some residents use several doctors. These factors can result in many medications being prescribed for a given resident. Often one drug interferes or reacts with another. Medications should be reviewed regularly by a pharmacist. Some residents end up taking more medicine than they need. Residents can also suffer more adverse effects from multiple drug interactions.


Dosage is the amount of a drug given for a specific, desired effect. There are several terms involving dosage. Minimum dose is the smallest amount of a drug that produces a desired effect. Maximum dose is the largest amount of a drug that produces a desired effect without signs of toxicity. Doctors will often start at one end of the range and gradually either increase or decrease the dose until a therapeutic dose is achieved. A therapeutic dose is the dose that may be required to produce a desired effect, and it is the dose customarily given to an adult. It produces the desired effect with the fewest adverse effects. A loading dose is an initial high dose to quickly elevate drug levels in the blood. A toxic dose is the amount of a drug that produces harmful side effects or signs of poisoning. Finally, a lethal dose is a dose that causes death.

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