1.11 Preparing for Administration
Monitoring the Effects
As medications are administered, the nurse should perform careful patient assessments, trend the assessment results, and monitor for side effects or toxic adverse effects. Drug dosages should be evaluated for potency in action. refers to the amount of the drug required to produce the desired effect. A drug that is highly potent may require only a minimal dose to produce a desired therapeutic effect, whereas a drug that has low potency may need to be given at much higher concentrations to produce the same effect. Consider the example of opioid versus non-opioid medications for pain control. Opioid medications often have a much higher potency in smaller doses to produce pain relief; therefore, the overall dose required to produce a therapeutic effect may be much less than for other analgesics.
The nurse preparing to administer medications must also be cognizant of drug selectivity and monitor for potential side effects and adverse effects. The of a drug refers to how readily the drug targets specific cells to produce an intended therapeutic effect. Drugs that are selective will search out target sites to create a drug action, whereas non-selective drugs may impact many different types of cells and tissues, thus potentially causing side effects. A occurs when the drug produces effects other than the intended effect. A side effect, although often undesirable, is generally anticipated by the provider and is a known unintended consequence of the medication therapy. Conversely, there are occasional occurrences of unanticipated effects that are dangerous to the patient. These dangerous occurrences are known as . Adverse effects are relatively unpredictable, severe, and are reason to discontinue the medication.[1]
- This work is a derivative of Principles of Pharmacology by LibreTexts licensed under CC BY-NC-SA 4.0. ↵
Antiprotozoal drugs target infectious protozoans such as Giardia, an intestinal protozoan parasite that infects humans and other mammals, causing severe diarrhea (see Figure 3.14 for a microscopic image of Giardia). [1]
Indications: Metronidazole is an example of an antiprotozoal antibacterial medication gel that is commonly used to treat acne rosacea, bacterial vaginosis, or trichomonas. Metronidazole IV is used to treat Giardia and also serious anaerobic bacterial infections such as Clostridium difficile (C-diff).
Mechanism of Action: Many antiprotozoal agents work to inhibit protozoan folic acid synthesis, subsequently impairing the protozoal cell.[2]
Special Administration Considerations: It can be administered PO, parenterally, or topically. Orally is the preferred route for GI infections. The nurse should monitor the patient carefully for side effects such as seizures, peripheral neuropathies, and dizziness. Psychotic reactions have been reported with alcoholic patients taking disulfiram.
Patient Teaching & Education
Patients taking antiprotozoal medications should receive education regarding the need for medication compliance and prevention of reinfection. They should be advised that the medication may cause dizziness and dry mouth. Additionally, the medication may cause darkening of the urine. They should also avoid alcoholic beverages during medication therapy to prevent a disulfiram-like reaction.
If patients are being treated for protozoal infections such as trichomoniasis, they should be advised that sexual partners might be sources of reinfection even if asymptomatic. Partners should also receive treatment.[3]
Patients teaching should include the avoidance of alcohol during therapy.
Now let's take a closer look at the medication grid in Table 3.17.[4]
Table 3.17 Metronidazole Medication Grid
| Class/Subclass | Prototype/Generic | Administration Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Antiprotozoal-antibacterial | metrogel | Check for allergies
Topical, vaginal, PO, or IV Don't give by IV push. Infuse over 30 to 60 minutes Contraindications: pregnancy, hypersensitivity, use of alcohol or disulfiram during therapy Use cautiously with hepatic impairment, blood dyscrasias or CNS diseases |
Improvement of symptoms | Seizures
Peripheral neuropathy Psychotic reactions Hepatotoxicity |
Critical Thinking Activity 3.17a
Using the above grid information, consider the following clinical scenario question:
A patient develops C-diff after taking multiple antibiotics for a non-healing wound. What medication is commonly used to treat C-diff, and what route is used?
Note: Answers to the Critical Thinking activities can be found in the "Answer Key" sections at the end of the book.
Antiprotozoal drugs target infectious protozoans such as Giardia, an intestinal protozoan parasite that infects humans and other mammals, causing severe diarrhea (see Figure 3.14 for a microscopic image of Giardia). [5]
Indications: Metronidazole is an example of an antiprotozoal antibacterial medication gel that is commonly used to treat acne rosacea, bacterial vaginosis, or trichomonas. Metronidazole IV is used to treat Giardia and also serious anaerobic bacterial infections such as Clostridium difficile (C-diff).
Mechanism of Action: Many antiprotozoal agents work to inhibit protozoan folic acid synthesis, subsequently impairing the protozoal cell.[6]
Special Administration Considerations: It can be administered PO, parenterally, or topically. Orally is the preferred route for GI infections. The nurse should monitor the patient carefully for side effects such as seizures, peripheral neuropathies, and dizziness. Psychotic reactions have been reported with alcoholic patients taking disulfiram.
Patient Teaching & Education
Patients taking antiprotozoal medications should receive education regarding the need for medication compliance and prevention of reinfection. They should be advised that the medication may cause dizziness and dry mouth. Additionally, the medication may cause darkening of the urine. They should also avoid alcoholic beverages during medication therapy to prevent a disulfiram-like reaction.
If patients are being treated for protozoal infections such as trichomoniasis, they should be advised that sexual partners might be sources of reinfection even if asymptomatic. Partners should also receive treatment.[7]
Patients teaching should include the avoidance of alcohol during therapy.
Now let's take a closer look at the medication grid in Table 3.17.[8]
Table 3.17 Metronidazole Medication Grid
| Class/Subclass | Prototype/Generic | Administration Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Antiprotozoal-antibacterial | metrogel | Check for allergies
Topical, vaginal, PO, or IV Don't give by IV push. Infuse over 30 to 60 minutes Contraindications: pregnancy, hypersensitivity, use of alcohol or disulfiram during therapy Use cautiously with hepatic impairment, blood dyscrasias or CNS diseases |
Improvement of symptoms | Seizures
Peripheral neuropathy Psychotic reactions Hepatotoxicity |
Critical Thinking Activity 3.17a
Using the above grid information, consider the following clinical scenario question:
A patient develops C-diff after taking multiple antibiotics for a non-healing wound. What medication is commonly used to treat C-diff, and what route is used?
Note: Answers to the Critical Thinking activities can be found in the "Answer Key" sections at the end of the book.
There are two major groups of parasitic helminths in the human body: the roundworms (Nematoda) and flatworms (Platyhelminthes). See Figure 3.15 for images of a tapeworm and a guinea worm.[9] Of the many species that exist in these groups, about half are parasitic and some are important human pathogens.
Indications: Anthelmintic medications target parasitic helminths.[10]
Mechanism of Action: Because helminths are multicellular eukaryotes like humans, developing drugs with selective toxicity against them is extremely challenging. Despite this, several effective classes have been developed. Many anthelmintic medications work by preventing microtubule formation within the parasitic cell, compromising glucose uptake. Others work by blocking neuronal transmission within the parasite, subsequently causing starvation, paralysis, and death of the worms. Additionally, many antihelminths inhibit ATP formation and impair calcium uptake inducing paralysis and death.[11]
Special Administration Considerations: Prolonged therapy using antihelmintic medication can result in liver damage and bone marrow suppression.
Patient Teaching & Education: Patients on antihelmintic drug therapy should receive special instruction to ensure rigorous hygienic precautions to minimize the risk of reinfection. They should also wash all bedding, linens, towels, and clothing following treatment to minimize reinfection risk.[12]
Now let's take a closer look at the medication grid on mebendazole in Table 3.18.[13]
Table 3.18 Mebendazole Medication Grid
| Class/Subclass | Prototype/Generic | Administration Considerations | Therapeutic Effects | Side/ Adverse Effects |
|---|---|---|---|---|
| Antihelmintic | mebendazole | Contraindicated during pregnancy; may cause fetal harm
To help prevent reinfection: -Wash hands and fingernails with soap often during the day, especially before eating and after using the toilet -Wash all fruits and vegetables thoroughly or cook them well -Wear shoes |
Elimination of worms | In prolonged treatment:
-Hepatic effects -Bone marrow suppression |
Critical Thinking Activity 3.18a
Using the above grid information, consider the following clinical scenario question:
A mother reports that her four-year-old son had a worm in his stool this morning. They live on a dairy farm. She reports that her son enjoys being in the barn during chore time, and it is common for the livestock to develop "worms." Mebendazole was prescribed. What patient teaching should the nurse provide to the child and the mother?
Note: Answers to the Critical Thinking activities can be found in the "Answer Key" sections at the end of the book.
