Mercury may be given by the mouth, by inunction, by hypodermic injection, or by fumigation. The intent should be to get the patient under its influence as rapidly as is consistent with safety. The most effective of these methods to which patients will ordinarily submit is that by inunction. This consists essentially in the use of mercurial ointment (blue ointment), of which 15 Gm. may be used daily or nightly, which should be thoroughly rubbed into some area of the body; the areas selected being changed at perhaps three-day intervals, in order that irritation, which its prolonged use produces, may be avoided. It takes considerable effort to so completely rub this in as to make most of it disappear, and it can be done more easily upon those parts of the body which are free from hair. It can be best done by employing someone for the purpose, but patients can be easily taught to use it themselves. There are upon the market, ointments containing mercury made with other excipients than lard, which are less uncomfortable to the skin and seem to be absorbed better; among these is a preparation made with a petroleum compound called vasogen, which may be procured in different strengths; that containing 33 per cent. or 50 per cent. is the best.
Inunction should be practised at least once every twenty-four hours, until either the gums become tender or swollen, with an offensive odor of the breath, or until the skin is irritated. The mouth should be protected by use of an astringent antiseptic mouth-wash, such as the following: Carbolic acid 10 parts, oil of wintergreen 1 part, tincture of myrrh 50 parts. A little of this solution in a tablespoonful or more of water makes a serviceable wash, which should be used several times a day. There are sanitaria and springs, or health resorts, in this country where a specialty is made of this manner of treatment. At these resorts inunction is practised freely and thoroughly, but the benefit which is obtained comes rather from the attention which patients give to the treatment, and their abstention from business or dissipation, than from any inherent medicinal features either in the mineral water or climate.
Under the influence of mercurial ointment alone, if a patient is willing to persist in its use, many cases of syphilis may be conducted to a successful termination; but its use is disagreeable to some people, and it may be impossible to resort to it for any great length of time. It has its inconveniences and disadvantages, but it should be applied in at least the first stages of the disease.
When mercurial ointment is seen to have made a distinctive impression upon the constitution of the patient it may be discarded and the treatment changed to the internal administration of the drug.
Mercurials may be given internally in any one of several different preparations. Hutchinson has recommended gray powder, in doses of ¹⁄₄ to ¹⁄₃ Gm. three or four times a day. Corrosive sublimate is a reliable form in which to administer mercury in doses which can be tolerated, from 1 to 2 Mg., three or four times a day. The red iodide may be given in similar doses, or the green iodide may be administered in doses of 0.15 to 2 Cg. These preparations sometimes irritate the intestinal tract and produce a certain amount of colic or looseness of the bowel. For the latter some astringent may be combined with the mercury, while intestinal pain may be checked by the use of extract of conium.
The hypodermic use of mercury can be made effective, but there are but few preparations which can be used that do not cause pain and subsequent irritation. Perhaps that which gives least pain is the sozoiodolate of mercury. This is sparingly soluble in water, dissolving in about 500 parts by weight. As the dose is 9 or 10 Cg., the amount of water necessary for this solution is so bulky that the dose should be injected into the gluteal region. Corrosive sublimate is also used in 1 per cent. solution, made up in common salt solution of the usual strength of 9 to 1000. Of this 10 minims represent a suitable dose to commence with, which may be increased to 30 or 40 minims when necessary. This should be given in the same region, the needle being driven in its full length perpendicularly to the surface. When this is done an injection is made into the muscle, where it seems to be more effective than in the subcutaneous fat. When the dose is increased to more than 20 minims a 2 per cent. solution may be used and the amount of fluid correspondingly reduced.
Fumigation is a method now not often adopted, calomel being used for the purpose, an ordinary cabinet hot-air bath confining the vapor about the patient. One treatment a day by either of these methods is usually sufficient.
About the initial sore dry calomel, pure or reduced with bismuth subnitrate, may be used. The condylomas met with about the perineum will often shrink and disappear under the influence of this application. Mucous patches should be treated with absolute cleanliness; in the mouth a wash of diluted hydrogen dioxide may be used, and the patches touched with a strong nitrate of silver solution, pure carbolic acid, or camphophenol. This will not prevent contagion from such a source, but will reduce it to a minimum beneficial in every respect.
The various eruptions of syphilis will disappear gradually under the influence of a local application of one of the mercurial preparations, either the ordinary mercurial ointment or ammoniated mercury.
In cases of inherited syphilis, especially in young children, a reduced mercurial ointment, or the use of gray powder (mercury with chalk) will give the best results. The dose should be regulated by the age of the patient; for instance, of the latter 1 to 2 Cg. for an infant. The iodides have also proved successful.