Human chorionic gonadotrophin comes on the market as a highly soluble powder which is the pure substance extracted from the urine of pregnant women. Such preparations are carefully standardized, and any brand made by a reliable pharmaceutical company is probably as good as any other. The substance should be extracted from the urine and not from the placenta, and it must of course be of human and not of animal origin. The powder is sealed in ampoules or in rubber-capped bottles in varying amounts which are stated in International Units. In this form HCG is stable; however, only such preparations should be used that have the date of manufacture and the date of expiry clearly stated on the label or package. A suitable solvent is always supplied in a separate ampoule in the same package.
Once HCG is in solution it is far less stable. It may be kept at room-temperature for two to three days, but if the solution must be kept longer it should always be refrigerated. When treating only one or two cases simultaneously, vials containing a small number of units say 1000 I.U. should be used. The 10 cc. of solvent which is supplied by the manufacturer is injected into the rubber- capped bottle containing the HCG, and the powder must dissolve instantly. Of this solution 1.25 cc. are withdrawn for each injection. One such bottle of 1000 I.U. therefore furnishes 8 injections. When more than one patient is being treated, they should not each have their own bottle but rather all be injected from the same vial and a fresh solution made when this is empty.
As we are usually treating a fair number of patients at the same time, we prefer to use vials containing 5000 units. With these the manufactures also supply 10 cc. of solvent. Of such a solution 0.25 cc. contain the 125 I.U., which is the standard dose for all cases and which should never be exceeded. This small amount is awkward to handle accurately (it requires an insulin syringe) and is wasteful, because there is a loss of solution in the nozzle of the syringe and in the needle. We therefore prefer a higher dilution, which we prepare in the following way: The solvent supplied is injected into the rubbercapped bottle containing the 5000 I.U . As these bottles are too small to hold more solvent, we withdraw 5 cc., inject it into an empty rubber-capped bottle and add 5 cc. of normal saline to each bottle. This gives us 10 cc. of solution in each bottle, and of this solution 0.5 cc. contains 125 I.U. This amount is convenient to inject with an ordinary syringe.
HCG produces little or no tissue-reaction, it is completely painless and in the many thousands of injections we have given we have never seen an inflammatory or suppurative reaction at the site of the injection.
One should avoid leaving a vacuum in the bottle after preparing the solution or after withdrawal of the amount required for the injections as otherwise alcohol used for sterilizing a frequently perforated rubber cap might be drawn into the solution. When sharp needles are used, it sometimes happens that a little bit of rubber is punched out of the rubber cap and can be seen as a small black speck floating in the solution. As these bits of rubber are heavier than the solution they rapidly settle out, and it is thus easy to avoid drawing them into the syringe.
We use very fine needles that are two inches long and inject deep intragluteally in the outer upper quadrant of the buttocks. The injection should if possible not be given into the superficial fat layers, which in very obese patients must be compressed so as to enable the needle to reach the muscle. Obviously needles and syringes must be carefully washed, sterilized and handled aseptically. It is also important that the daily injection should be given at intervals as close to 24 hours as possible. Any attempt to economize in time by giving larger doses at longer intervals is doomed to produce less satisfactory results.
There are hardly any contraindications to the HCG method. Treatment can be continued in the presence of abscesses, suppuration, large infected wounds and major fractures. Surgery and general anesthesia are no reason to stop and we have given treatment during a severe attack of malaria. Acne or boils are no contraindication; the former usually clears up, and furunculosis comes to an end. Thrombophlebitis is no contraindication, and we have treated several obese patients with HCG and the 500-Calorie diet while suffering from this condition. Our impression has been that in obese patients the phlebitis does rather better and certainly no worse than under the usual treatment alone. This also applies to patients suffering from varicose ulcers which tend to heal rapidly.