MENGHITUNG DOSIS OBAT - Materi Dasar Dasar Kefarmasian Kelas X SMK Farmasi

Summary

This educational script provides a comprehensive guide on calculating medication doses, specifically designed for pharmacy students. It covers various types of doses, such as therapeutic, maximum, toxic, and initiation doses. The script explains how to adjust doses based on age, weight, and other factors like health status and drug interactions. It includes formulas for calculating doses for children, including infants, based on age and weight. Practical examples demonstrate how to calculate the correct dose for medications, ensuring safety and effectiveness. The content aims to build a solid foundation in understanding and applying dose calculations in pharmacy practice.

Takeaways

• 😀 Dosing is the amount of a drug given to a patient for treatment, and it can vary based on different factors such as age, weight, and health conditions.
• 😀 There are various types of dosages: therapeutic dose (normal treatment), maximum dose (safe limit), toxic dose (leads to poisoning), LD50 (lethal for 50% of animals), and LD100 (lethal for 100% of animals).
• 😀 The initiation dose is given at the start of therapy to reach the desired therapeutic effect, and the maintenance dose is used to maintain the therapeutic concentration.
• 😀 The maximum dose varies by age, with adults aged 20-60 years receiving the full dose, and those above 60 years receiving a reduced dose.
• 😀 For people over 60, doses decrease progressively: 43-45% for those 60-70, 75% for those 70-80, and 25% for those over 90 years old.
• 😀 The combined maximum dose for multiple medications must be calculated carefully to avoid exceeding the safe limit of 100% of the maximum dose for one drug.
• 😀 Factors affecting dosage include age, weight, gender, health status, tolerance, drug form (oral/injection), and potential drug interactions.
• 😀 A formula for children under 8 years old: Dosis Anak = (N / M + 12) * Dosis Dewasa, where N is the child’s age and M is a fixed factor.
• 😀 For children over 8, the formula is Dosis Anak = (N / 20) * Dosis Dewasa, while for infants (0-12 months), it's Dosis Bayi = (N / 120) * Dosis Dewasa.
• 😀 Practical formulas based on body weight (like those from the U.S. and Germany) help calculate the maximum safe dose based on a child's weight.
• 😀 The transcript provides an example of calculating the maximum dose of atropine sulfate for a 12-year-old child, ensuring the calculated dose is within the safe limits.

Q & A

What is the definition of a drug dosage?

A drug dosage refers to the amount of a drug that can be used or given to a patient, whether for internal or external use.

What is the difference between therapeutic dosage and maximum dosage?

Therapeutic dosage, also known as medicinal dosage, is the amount of a drug given under normal conditions to treat a patient, while maximum dosage is the highest amount of a drug that can be safely administered to an adult in a single dose or per day.

What does LD50 represent in drug dosage terminology?

LD50, or lethal dose 50, is the amount of a substance that causes death in 50% of a test animal population.

How is the dosage for elderly patients different from that of adults?

The dosage for elderly patients is generally lower than that for adults, as their physical growth and metabolism may have declined. For example, patients aged 60-70 years receive 43-45% of the adult dosage, while patients over 90 years old may receive only half of the adult dosage.

What is the formula for calculating drug dosage for children under 8 years old?

The formula for calculating the dosage for children under 8 years old is: (Age / (Age + 12)) * Adult dosage.

How do factors like age, weight, and gender affect drug dosage?

Drug dosage can vary based on age, weight, and gender. For example, children and elderly individuals typically require adjusted dosages. Gender differences may also influence sensitivity to certain medications, leading to different dosages for males and females.

How does the route of administration (oral vs. injection) impact drug dosage?

The method of drug administration affects how the body absorbs and processes the medication. For instance, oral dosages are typically higher than those for injection, as injections tend to provide more direct and efficient absorption.

What are 'maximum combined dosages' in a prescription?

Maximum combined dosages refer to the total amount of multiple medications in a prescription that work together or in a similar manner, ensuring that the combined total does not exceed the safe limits for a single dose or daily usage.

What is the formula for calculating drug dosage based on a child's weight?

To calculate the drug dosage for a child based on their weight, you can use the formula: (Child's weight in kg / 68) * Maximum adult dosage.

What should be considered when determining the appropriate dosage for a patient with a chronic illness?

Patients with chronic illnesses, such as kidney or liver disease, may require dosage adjustments. Their underlying condition could affect the metabolism or excretion of the drug, necessitating a lower dose to prevent toxicity or adverse effects.