Terms used in prescription writing

The Cambridge medical library has every issue of The Lancet since 5 October, 1823 (the first issue). Glancing through some nineteenth century case histories I frequently found myself stuck. The physicians concerned would usually include their prescriptions, but as I could not read them I could not understand what treatments were being inflicted on the poor patients. I am grateful to Olwen Imrie, retired dispenser for providing the information contained on this page, and to Wendy Roberts, Medical Librarian at the University of Cambridge School of Clinical Medicine. Additional information from Hale-White's Materia Medica Pharmacy and Therapeutics, 29th ed. 1952.

• The structure of a prescription
• Weights
• Measures
• Instructions to dispenser
• Instructions to patient
• Manner of administration

Each prescription will have
a Superscription (R., meaning Recipe "Take"),
an Inscription (the list of ingredients),
a Subscription (directions to the dispenser),
a Signature (directions to the patient), and
the intials of the prescribing doctor.

A medicine may have four parts:
the Basis (principal active ingredient),
the Adjuvant (which assists its action),
the Corrigent (which correct its operation), and
the Constituent (vehicle or excipient which imparts an agreeable form).
Not every medicine may have a corrigent or constituent.

The following prescription is for Pilula Colocynthidis & Hyoscyami which is a hydrogogue cathartic (powerful purgative). This medicine was used only once to purge the gut and is not for regular use. It is extremely irritant to the gut and is contraindicated in patients for which transit of the medicine may be delayed. This medicine would never be used today, but was in regular use up until the late 1950's.

R_x
colocynthis gr.
aloes gr.ii.
scammonii gr.ii.
hyoscami gr.
saponis duri q.s.
syrupi glucosi liquidi q.s.
- Ft. pil.

Sum. stat.
Sig. "To be taken immediately."

A.B.C.

Take (superscription)
1 grain of colocynth (basis. Dried pulp of Citrullus colocynthis)
2 grains of aloes (adjuvant)
2 grains of scammony (adjuvant. Gum resin from the root of Convovulus scammonia.)
1 grain of hyoscyamus (corrigent)
sufficient hard soap (constituent. Formed from the action of caustic soda on olive oil.)
sufficient glucose syrup (constituent)
- form into a pill.

Let it be taken immediately. (subscription)
On the label, write, "To be taken immediately." (signature)

A.B.C. (doctor's initials)

Weights (Apothecaries)
Granum	gr.	grain	64.8 mg
Scrupulus		scruple (20 grains)	1.30 g
Drachma	, dr.	dram (3 scruples)	3.89 g
Uncia	, oz.	ounce (8 drams)	31.1 g
Libra	lb.	pound (12 ounces)	373 g
Semigranum Granum dimidium Grani dimidium	gr.ss., gr.½	half a grain	32.4 mg
Granum cum semisse	gr.iss.	grain and a half	97.2 mg
Quarta pars grani Grani quadrans	gr.¼	quarter of a grain	16.2 mg

Measures
Minimum		minim	0.0592 ml (British Imperial)	0.0616 ml (US)
Drachma fluida	fl., fl.dr.	fluid dram	3.55 ml (60 fluid minims)	3.70 ml (60 fluid minims)
Uncia fluida	fl., fl.oz.	fluid ounce	28.4 ml (8 fluid drams)	29.6 ml (8 fluid drams)
Octarius	O.	pint	568 ml (20 fluid ounces)	473 ml (16 fluid ounces)
Congius	Cong., C.	gallon	4550 ml (2 pints)	3790 ml (2 pints)

Domestic measures
Gutta	gtt.	drop
Cochleare parvum/minimum	coch. parv./min.	teaspoon (1 fl. dr.)
Cochleare modicum/medium	coch. mod./med.	dessertspoon (2 fl. dr.)
Cochleare amplum/magnum	coch. ampl./mag.	tablespoon (3 fl. dr.)
Cyathus vinarius/vinosus	cyath.vin.	wineglassful (2-3 oz.)
Cyathus magnus	cyath.mag.	tumblerful (10 oz.)
Poculum		teacupful (5-6 o.z)
Pugillus		a pinch
Pollex		an inch

Instructions to dispenser
Recipe	, Rx, R.	take
Misce	M.	mix
Solve	S.	dissolve
Coque	coq.	boil
Cola	col.	strain
Filtra	fil.	filter
Adde		add
Repete		repeat
Tere		rub
Divide	div.	divide
Mitte		send
Mittendus		to be sent
Habeat		let him have
Fiat/Fiant	Ft.	let it be made
Ampulla	amp.	an ampoule (containing liquid for injection)
Balneum	baln.	a bath
Bolus		a bolus (originally a large pill, later = a confection)
Capsula	caps.	a capsule
Capsula amylacea		a cachet (medicine coated in a rice-flour paste)
Capsula gelatina		a gelatine capsule
Cataplasma	catapl.	a poultice
Charta		a paper/a powder
Clyster		an enema
Collyrium	collyr.	an eye-wash
Collutorium	collut.	a mouth wash
Confectio	confect.	a confection (medicine prepared with sugar, syrup or honey)
Conserva		a conserve (medicine prepared with sugar or syrup = a confection)
Cremor	crem.	a cream
Electuarium	elec.	an electuary (medicine prepared with sugar, syrup or honey = a confection)
Emulsio	emuls.	an emulsion
Emplastrum	empl.	a plaster
Enema	enem.	an enema
Essentia		an essence (solution of volatile oil in rectified spirit, usually 1 part into 5)
Extractum		an extract (soluble matter in animal or vegetable tissue extracted with water or alcohol then evaporated)
Fomenta		a foment (flannel wrung out in hot water to which a drug may or may not have been added)
Gargarisma	garg.	a gargle
Haustus	haust.	a draught
Inhalatio	inhal.	an inhalation
Injectio	inj.	an injection
Insufflatio	insuf.	an insufflation
Lamella		a lamella (small thin disc made with gelatin and glycerin for dropping into the eye)
Linimentum	lin.	a liniment (liquid or semi-liquid for applying on the skin for relieving pain)
Lotio	lot.	a lotion
Massa	mass.	a mass
Mel		medicine mixed with honey.
Mistura	mist.	a mixture
Mucilago		a mucilage (viscid solution of gum in water, used for suspending insoluble medicines)
Nebula	neb.	a spray
Oculenta		an ointment for the eye
Oblatum		a cachet
Pasta	past.	a paste
Perla		a perle (small gelatin capsule)
Pessus	pess.	a pessary
Pigmenta	pig.	a paint (medicine in a liquid preparation to be applied to the skin by brush)
Pilula	pil.	a pill
Pulvis	pulv.	a powder
Suppositorium	suppos.	a suppository
Syrupus		a syrup
Trochiscus	troch.	a lozenge (medicated candy)
Unguentum	ung.	an ointment
Vina	vin.	a wine (weak tincture, the drug being extracted by sherry)
Ana	aa.	of each
Ad		to, up to
Adde	ad.	add
Quantum sufficiat Quantum satis	q.s.	sufficient
Lege artis	leg.art.	in the proper way
Secundum artem	sec.art.	in the proper way
Ad libitum	ad lib.	at pleasure
Signetur	S., Sig.	let it be labelled
Signa	S., Sig.	label
Datur	D.	let it be given
Da	D.	give

Instructions to Patient
Sumat	Sum.	let him take
Sumatur		let it be taken
Capiat	Cap.	let him take
Capiatur		let it be taken
Admove	Admov.	apply
Admoveatur Applicetur		let it be applied
Ex aqua	ex.aq.	in water
More dicto Modo dicto	m.d.	as directed
Post, ante, inter, cibos, cibum		after, before, between, meals
Cum cibo/cibis		with meals
Statim	stat.	immediately
Mane		in the morning
Nocte		at night
Vespere		in the evening
Meridie		at mid-day
Hora somni Hora decubitus		at bedtime
Hodie		to-day
Cras		to-morrow
Hac nocte		to-night
Omni die Omni in die Quotidie in dies	o.d.	every day
Omni mane	o.m.	every morning
Omni nocte	o.n.	every night
Omni die secunda		every second day
Minitum	minit.	minute
Semel die		once a day
Bis die	b.d.	twice a day
Bis in die	b.i.d.	twice a day
Bis die sumendus	b.d.s.	twice a day
Ter in die	t.i.d.	thrice a day
Ter die sumendus	t.d.s.	thrice a day
Quater in die	q.i.d.	four times a day
Quater die sumendus	q.d.s.	four times a day
Saepe in die		often during the day
Jentaculum		breakfast
Prandium		dinner
Coena		supper
Omni hora		every hour
Omni quadrante horae		Every quarter-hour
Omni semihora		every half-hour
Omni hora secunda		every two hours
Omni hora tertia		every three hours
Quattuor quaque hora (sumendo)	q.q.h.	every four hours
Sexta quaque hora (sumendo)		every six hours
Pro re nata	p.r.n.	when required
Subinde, frequenter		frequently
Si opus sit	s.o.s.	when necessary
Ubi dolor urgeat		when the pain is violent
Febri adstante		when the fever is on

Manner of Administration
Phiala prius agitata	p.p.a.	the bottle being previously shaken
Ex cyatho aquae		in a glass of water
Donec alvus dejecerit		until the bowels have been moved
Alvo adstricta/laxata		the bowels being confined/loose
Donec sudor prodeat		until sweat is produced
Per fistulam vitream		through a glass tube
Donec evanescant symptomata		until the symptoms disappear
In aurem (oculum, &c.) instillari		to be dropped into the ear (eye, etc.)
Injiciatur		to be injected
Pars affecta fricetur linimento (unguento, &c.)		the affected part to be rubbed with the liniment (ointment, etc.)
Applicatur loco affecto		to be applied to the affected part
Usque ad vesicationem		to be applied until vesication is produced

This page last updated 27 Aug 1999.
Counter running since 16 May 1999.

Conversions and explanations of the more obscure terms are taken from the Merriam-Webster Dictionary.