Ordering and Quantifying Medicines

Why ordering needs method

If a unit orders too little, it runs out and patients go without. If it orders too much, money is tied up and medicines expire. A good order is based on data, worked out in steps, and written on a form that can be checked.

The steps for ordering

1. Collect data for estimating the medicines needed.
2. Decide the ordering interval, which is how often to order.
3. List the common medicines that are needed.
4. Calculate the amount of each medicine needed in the ordering interval, based on local and seasonal use.
5. Complete the medicines requisition form.
6. Calculate the cost of the medicines ordered.

Step 1: Data collection

The data comes from records, not from memory:

• issue records or sales records for the last few months;
• the number of patients treated, and the illnesses seen;
• the stock on hand and any stock already on order;
• expiry dates, so that stock about to expire is counted properly;
• information on seasons and outbreaks.

Average monthly consumption (AMC) is the average quantity used each month. Leave out months when the medicine was out of stock, since use would have been higher.

Step 2: The ordering interval

The ordering interval is the time between orders, for example every month or every three months.

It depends on how far the supplier is, how reliable transport is, the money available and the storage space.

Step 3: The list of medicines

Order from the essential medicines list for the level of care, and choose the medicines for the illnesses that are common locally. See the lesson on setting up a drug revolving fund for more on this.

Step 4: Calculating the amount

order quantity = AMC × (ordering interval + lead time + safety stock)
                 − stock on hand − stock already on order

All three time periods are in months. The lead time is how long the supplier takes to deliver. The safety stock is an extra cushion for delays or a sudden rise in use.

Worked example

AMC = 300 tablets. Interval 2 months, lead time 1 month, safety stock 1 month. Stock on hand 400.

1. Months of cover = 2 + 1 + 1 = 4
2. Needed = 300 × 4 = 1 200
3. Order = 1 200 − 400 = 800 tablets

Seasonal and local use

Use is not always the same every month. Adjust the average when you know that demand will change:

• malaria cases rise in the rainy season;
• cough and cold medicines rise in the dry (harmattan) season;
• vaccines are needed in larger amounts before an expected outbreak, such as measles vaccine before a measles outbreak;
• a new clinic day or a new population changes the number of patients.

Example. Normal use is 100 doses a month. A 50% rise is expected.

• Expected use = 100 + (100 × 50 ÷ 100) = 100 + 50 = 150 doses a month
• Use this figure in place of the AMC for the period of the outbreak.

Step 5: The requisition form

A requisition form is the written request for medicines. It usually shows:

• the name of the unit and the date;
• the name, form and strength of each medicine, in the same way as on the supply list;
• the unit of issue (tablet, bottle, pack);
• the stock on hand, the average monthly consumption and the quantity requested;
• the signature of the person who made the request, and of the person who approves it.

Write clearly, so that the supplier sends exactly what you need. A form with missing or unclear details is returned or leads to the wrong supply.

Step 6: Costing the order

cost of an item = quantity × unit cost
cost of the order = total of all the items

Example. 500 capsules at ₦20 each and 200 tablets at ₦5 each.

Use the current price. Compare the total with the money available before sending the order. All amounts in these lessons are made up for practice.

Common mistakes