Definition of suppositories
Normally, when we hear about "suppositories" we immediately refer to pharmacological preparations to be administered rectally; in reality, the term "suppository" is more general and, in addition to indicating this precise route of administration, it also refers to the application of the drug directly into the vagina (vaginal ovules) or into the urethra (urethral suppository).
Suppositories in general, and suppositories in particular, are solid pharmaceutical forms containing an active principle dissolved in a fatty or in any case waxy medium; the particular composition of the excipients allows the drug to liquefy, therefore to be released and to diffuse after a very short period of time from its insertion into the rectum, vagina or urethra.
Suppositories exert their therapeutic action both locally and systemically: to give some examples, suppositories formulated with glycerin act locally, favoring evacuation in a short time, while those prepared with paracetamol or anti-inflammatory drugs can be administered rectally to lower fever or to relieve headaches and other types of pain.
Active ingredients and types
The active ingredient that makes up the suppositories is chosen according to the disorder to which you want to remedy; the drug is always formulated in association with excipients, useful for containing the active principle, favoring its fusion in contact with body heat, and forging the suppository.
The peculiarity of the suppositories lies precisely in the peculiar solid composition: introduced into the organism (in the rectum, in the vagina or in the urethra) in solid form, the suppository dissolves rapidly and, subsequently, is absorbed thanks to the blood vessels.
Some suppositories are formulated with an oil base, such as cocoa butter, in which the active ingredient is dissolved; other suppositories - especially those for vaginal and urethral use - consist of propylene glycol, a water-soluble excipient (soluble in water). Glycerin suppositories are instead composed of glycerol and gelatin, and are normally used for laxative purposes.
There are also the so-called liquid suppositories, in which the administration of the drug (usually a laxative) is carried out through a special syringe, directly into the rectum.
RECTAL SUPPOSITORIES can determine their therapeutic action at a local or systemic level:
- TO local level, the suppositories are formulated with drugs capable of promoting evacuation: the active laxative principles - generally emollients - which make them up, acting directly on the anal mucosa, induce evacuation through lubrication of the rectum. These suppositories are normally formulated with a glycerin base. Furthermore, at a local level, the suppositories can be formulated with active ingredients capable of exerting a beneficial action for the treatment of hemorrhoids: in this case, the rectal suppositories are formulated with substances with a vasoconstrictive action.
- TO systemic level, suppositories can be used for various purposes: in this case, it is recommended to introduce the suppository after evacuation, to prevent it from being expelled before being absorbed by the body. To act on a systemic level, the active ingredient with which the rectal suppository is formulated is rapidly absorbed by the mucous membrane of the rectum which, as we have observed, is rich in blood vessels: after the drug has reached the circulation, it can reach the target organs. The active ingredients most used to prepare rectal suppositories of this type are: paracetamol (to lower fever), promethazine (to treat nausea and vomiting), acetylsalicylic acid and opiates (to reduce pain), etc.
VAGINAL SUPPOSITORIES include a series of pharmacological preparations for purely gynecological use: among the vaginal suppositories, we remember: vaginal suppositories, vaginal tablets and creams to be applied internally through a special cannula.
Even this category of drugs can exert its therapeutic effect at a local and systemic level: some vaginal suppositories are formulated with a mixture of lactobacilli, useful for ensuring the balance of the vaginal bacterial flora; others are composed of antibiotics (for example, to eradicate bacterial infections, caused by Trichomonas vaginalis, Mycoplasma hominis, Neisseria gonorrhoeae, etc.), antifungals (for the treatment of Candida albicans) and antivirals (to treat virus infections, such as those caused by Herpes simplex).
URETHRAL SUPPOSITORIES are indicated to treat male disorders, including erectile dysfunction and impotence; in the United States, the trade name of these particular suppositories is MUSE, an acronym for Medical Urethral System for Erection. These particular pharmacological formulations are modular transurethral devices, in which the drug is introduced into the "urethra through the" special "piston" applicator.
Rectal Suppositories: Advantages and Disadvantages
Many doctors recommend taking a certain drug rectally, in the form of a suppository: the advantages derived from this route of administration are indeed remarkable; there are, however, the disadvantages. But let's see them in more detail.
Unlike drugs administered orally, suppositories to be taken rectally do not cause gastric irritation, since they do not pass through the stomach.
Another important advantage, which differentiates rectal suppositories from oral tablets, concerns enzymes: drugs that would be inactivated by gastric enzymes remain so when applied rectally.
In case of vomiting, even after taking a rectal suppository, the characteristic problem of oral drugs does not arise: as we know, when it occurs before the active ingredient has been completely absorbed by the body, vomiting can compromise the effectiveness of the drug. . For rectal suppositories, this problem does not exist.
Suppositories are particularly suitable following gastrointestinal surgery, as well as in children and the elderly who find it difficult to swallow medicines by mouth.
If up to this point we have analyzed suppositories as an exceptional pharmaceutical mode of administration, we must not forget the possible disadvantages.
Although the rectal mucosa is rather rich in blood vessels, the suppository is placed in contact with a markedly reduced absorption area compared to the intestinal one; consequently, the absorption of the drug via the rectum is reduced when compared to that of the medicines taken. orally. Furthermore, the absorption of the drug formulated in the form of suppositories, as well as its availability, is neither constant nor predictable: depending on the point at which the active ingredient reaches, it can be absorbed by the lower hemorrhoidal plexus, or by the middle or middle tract. superior: for this reason, the drug may or may not pass through the liver.
The area in which the rectal suppository exerts its action is subject to irritation; not surprisingly, many suppositories are formulated with laxative active ingredients, which favor evacuation by exerting a mild irritation of the anal mucosa.
Another important element should not be underestimated: the bacteria that colonize the anus and rectum can sometimes inactivate part of the active ingredient, thus reducing the activity of the drug.
The table summarizes the key concepts just described
Advantages of rectal suppositories
Disadvantages of suppositories rectally
- They do not cause gastric irritation
- The drug is not inactivated by gastric enzymes
- The drug is also absorbed in case of vomiting
- The laxative effect of some drugs formulated as suppositories is almost immediate
- Indicated for those who complain of difficulty swallowing tablets orally and for those who have undergone gastrointestinal surgery
- Rectal area: less absorption than the intestine
- Inconsistent and unpredictable drug absorption
- Area subject to irritation
- Possible inactivation of the drug by bacteria
- Rather slow absorption of the drug
To obtain the maximum therapeutic efficacy, the correct insertion of the suppository is very important; Below are general guidelines for correctly taking a rectal suppository.
- Wash your hands thoroughly.
- If the suppository is soft, it is advisable to place it in the refrigerator for a few minutes, or to leave it in cold water (before opening the package) to allow the excipients to solidify the suppository.
- Remove the trim wrap.
- If necessary, cut the suppository with a soft cloth (according to the dosage prescribed by the doctor).
- If necessary, wear a latex glove.
- It is advisable to lubricate the upper part of the suppository, to facilitate its insertion into the rectum.
- Lie on your side, with one leg resting on the ground extended, the other slightly bent forward, towards the abdomen.
- Lift one buttock and insert the suppository into the rectum, so that it passes through the anal muscle sphincter.
- It is advisable to keep the position lying on your side for a few minutes, to prevent the suppository from being expelled.
- Wash your hands thoroughly.