Calculating Dosage Using Alligation Method

12 Questions

What is the molarity of Na in the serum?

140 mEq/L

How would you prepare 100ml of 10% w/v iodine solution using 5% w/v and 20% w/v iodine solutions?

Take 67ml of 5% w/v and 33ml of 20% w/v iodine solution.

What is the volume of 20% w/v iodine solution needed to produce 100ml of 10% w/v iodine solution?

33ml

In what proportion should 80% w/v, 70% w/v, and 50% w/v solutions be mixed to produce 100ml of 60% w/v solution?

Mix 25ml of 80% w/v, 25ml of 70% w/v, and 50ml of 50% w/v solutions.

What is the proportion of 80% w/v and 50% w/v solutions to create a possible mixture of 60% w/v?

20 parts of 80% w/v and 10 parts of 50% w/v

How many parts of 70% w/v and 50% w/v solutions are needed to form a mixture of 60% w/v?

10 parts of 70% w/v and 10 parts of 50% w/v

What are the amounts in milliliters of the 80% w/v, 70% w/v, and 50% w/v parts in a total mixture of 100ml at 60% w/v?

20ml of 80% w/v, 20ml of 70% w/v, 60ml of 50% w/v

How can you mix 80% w/v, 70% w/v, 50% w/v, and 40% w/v solutions to produce a 60% w/v mixture of 100ml?

The aligation method can be used to determine the proportions of each solution needed.

What is the total number of parts in the mixture of 80% w/v, 40% w/v, 70% w/v, and 50% w/v solutions?

60 parts

How many milliliters are needed for the 70% w/v solution in a 100ml mixture?

16.7ml

What is the rule of thumb for calculating dosage using the largest and smallest numbers?

Subtract the smallest percentage from the largest percentage to find the parts of each solution.

How would you calculate the dosage for a patient weighing 75kg who needs Ivermectin 200 mcg/kg/dose using 3mg tablets?

Calculate the total dosage required (200 mcg/kg x 75kg), then divide by the tablet strength (3mg) to find the number of tablets needed.

Study Notes

Molarity of Na in Serum

The molarity of Na in the serum is not specified.

Preparing Iodine Solutions

To prepare 100ml of 10% w/v iodine solution, you need to mix 5% w/v and 20% w/v iodine solutions.
The volume of 20% w/v iodine solution needed to produce 100ml of 10% w/v iodine solution can be calculated.

Mixing Iodine Solutions to Produce 60% w/v Solution

To produce 100ml of 60% w/v solution, you need to mix 80% w/v, 70% w/v, and 50% w/v solutions in a specific proportion.
The proportion of 80% w/v and 50% w/v solutions to create a possible mixture of 60% w/v is a specific ratio.
To form a mixture of 60% w/v, you need a certain number of parts of 70% w/v and 50% w/v solutions.
The amounts in milliliters of the 80% w/v, 70% w/v, and 50% w/v parts in a total mixture of 100ml at 60% w/v can be calculated.

Mixing Multiple Iodine Solutions to Produce 60% w/v Solution

You can mix 80% w/v, 70% w/v, 50% w/v, and 40% w/v solutions to produce a 60% w/v mixture of 100ml.
The total number of parts in the mixture of 80% w/v, 40% w/v, 70% w/v, and 50% w/v solutions can be calculated.
The amount of 70% w/v solution needed in a 100ml mixture can be calculated.