This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
(1) Quinia lowers the body temperature very moderately in the healthy subject; very markedly in the pyrexia of many acute specific fevers. It appears to be difficult to lower the normal temperature by drugs, as compensating mechanisms are probably brought into play; but the rise of temperature and the perspiration normally produced by muscular exercise are prevented by quinia. In malarial fevers, typhoid, acute pneumonia, and some forms of hectic and other periodic fevers, the defervescent effect of quinia is unquestionable.
These two sets of effects taken together point to a powerful action of quinia in reducing the metabolism of the body, of which heat and the excretions are the two most measurable products. This conclusion is supported by other facts, observed out of the body, viz.: That (3) a solution of albumen cannot be converted into peptones in an atmosphere of ozone if quinia be present. (4) Healthy pus and fresh vegetable juices lose their ozonising power if mixed with quinia. (5) Phosphorescent infusoria (rapidly oxydating protoplasmic masses) lose their phosphorescence in the presence of quinia. (6) Fungi absorb oxygen less readily, and many forms of fermentation are arrested, in the presence of quinia. These facts indicate that quinia so combines with living cellular protoplasm as to render it less able to incorporate oxygen, and more resistant of vital change (metabolism). Now we have already seen that the oxygen actually in the corpuscles is bound more firmly to them by quinia. We may therefore conclude that the effect of quinia in the body is to check metabolism by interfering with oxygenation, with the oxydation of protoplasm generally, and with the associated action of ferments. Thus the fall of temperature produced by quinia is due to diminished production of heat in the body, not to increased loss of heat; it is effected through the tissues, not through the heat-regulating centre; and the fever-causing (pyrogenic) processes themselves (probably allied to fermentations) are also controlled by the drug, which affects their organic causes, whether living organisms or complex chemical substances.
An action such as this upon the processes of nutrition, though it might escape the notice of an ignorant observer, is more "powerful" even than the action of morphia upon a highly sensitive nervous mechanism such as the convolutions.
Turning to the other systems, we find that whilst small doses of quinia accelerate the heart and raise the pressure, as we saw when considering the stomachic effect, full doses slow and weaken the heart and. lower the pressure. These effects are due to direct depression of the cardiac ganglia and muscle, and of the vessel walls and their centre, not of the cardiac centre. Respiration is accelerated by medium doses, depressed by large doses; and death, should it occur, is referable to respiratory and cardiac failure. The spleen is reduced in size, and hardened.
4. specific uses.
1. Malaria is remarkably benefited by quinia, which is an antiperiodic or direct specific, whether given to persons exposed to the morbid influence as a prophylactic measure, or to the subjects of ague. It acts best in fresh cases, the first dose of 10 gr. being given at any time with relation to the attack, and similar doses repeated five hours before the time of the next paroxysm. All forms of malarial fever are benefited by quinia, as well as many diseases and disorders of malarial origin, such as neuralgia, hepatic disturbances, etc. The functions of the liver must be maintained during this treatment of ague, and the quinia may be combined with morphia if its effects are not well marked..
2. Febrile conditions in general are relieved by the antipyretic effect of quinia, for instance, acute pneumonia, typhoid fever, puerperal fever, and septicaemia, the exanthemata, and acute rheumatism; but generally in very different degrees, so that its value is denied in some or all of them. To be of use the quinia must be very freely given (10 to 20 grains) as single doses when the temperature reaches a definite height, say 104° Fahr. Even if apyrexia do not follow, the drug may be of much benefit. In hectic fever quinia is rarely of much service; and in purely symptomatic fever, of still less use.
3. In splenic enlargement of malarial origin quinia is given with success, and in some cases of leukaematous hypertrophy.
4. In painful nervous affections, especially headache and face-ache, the effect of quinia is well marked. Some of these cases are malarial (brow ague); but ordinary facial neuralgia and toothache will frequently yield to it. Yet quinia possesses no direct action on peripheral nerves.
5. The tonic action of quinia has been already referred to. This is also due in part to its removal of fever, and thus of restlessness, sleeplessness, and want of appetite. It further modifies the processes of "secondary digestion" in the liver, and may relieve hepatic disorder due to free living, especially in persons who have resided in the tropics.
Quinia is excreted chiefly in the urine, as the amorphous alkaloid; partly as resinoid and crystalline derivates. In passing through the urinary organs it is slightly diuretic, and occasionally irritates the passages. It also escapes by the skin, diminishing the perspiration, and very rarely causing an itching eruption, which resembles scarlatina or measles. All the mucous secretions, the milk, and pathological fluids may also contain quinia.