chemistry

Practolol

Practolol is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Practolol rather than just read about it. In short: Practolol (Eraldin, Dalzic, Praktol, Cardiol, Pralon, Cordialina, Eraldina, Teranol) is a beta blocker selective for the β1-adrenergic receptor that has been used in the emergency treatment of cardiac arrhythmias. Practolol is no longer used as it is highly toxic despite the similarity of its chemical formula to propranolol.

Key takeaways

Practolol belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Practolol to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Practolol from memory before moving on to harder problems.

Reference excerpt

Practolol (Eraldin, Dalzic, Praktol, Cardiol, Pralon, Cordialina, Eraldina, Teranol) is a beta blocker selective for the β1-adrenergic receptor that has been used in the emergency treatment of cardiac arrhythmias. Practolol is no longer used as it is highly toxic despite the similarity of its chemical formula to propranolol.

Side effects Side effects are similar to those of other beta blockers, such as bronchoconstriction, cardiac failure, cold extremities, fatigue and depression, hypoglycaemia. Furthermore, chronic use of practolol may cause oculomucocutaneous syndrome, a severe syndrome whose signs include conjunctivitis sicca and psoriasiform rashes, otitis and sclerosing serositis. This syndrome has not been observed with other such beta blockers. After its introduction, keratoconjunctivitis sicca, conjunctival scarring, fibrosis, metaplasia, and shrinkage developed in 27 patients as an adverse reaction to practolol. Rashes, nasal and mucosal ulceration, fibrous or plastic peritonitis, pleurisy, cochlear damage, and secretory otitis media also occurred in some cases. Three patients suffered profound visual loss though most retained good vision. Symptoms and signs improved on withdrawal of the drug, but reduction of tear secretion persisted in most patients.

Chemistry The experimental log P of practolol is 0.79 and its predicted log P ranges from 0.53 to 0.83. It is a hydrophilic or low-lipophilicity beta blocker.

Synthesis The part of the structure coming from (1) is based on paracetamol.

A synthesis is available which relates the absolute configuration of the more potent optical isomer to (+)-lactic acid. The glycerol derivative (2) is available from D-mannitol and retains optical activity as the two 1° alcohol functions are differentially protected. Displacement with sodium p-acetamidophenoxide (1, deprotonated paracetamol) gives 3 which is deprotected with dilute acid, the primary alcohol function is selectively reacted with one molar equivalent of tosyl chloride and pyridine, then treated with NaOH in dimethylsulfoxide to yield 3. Epoxide opening with isopropylamine leads to optically active prolactolol (4).

History The compound was studied by scientists at the Research Department of the ICI Pharmaceuticals Division in Alderley Park with physiologists at the University of Leeds in the early 1970s when it was known as compound ICI 66082; they utilised dogs, cats and rats in their investigations. Earlier research had also been carried out as early as 1967 on this and similar molecules by other research teams also with ICI.

Society and culture

Market withdrawal This drug has been withdrawn from the market in India.

References

External links Scientific information / studies Guinea Pig study from 1975 Liver effect study from 1981 Study of uses during surgery Molecular structure General information Diseases Database (DDB): 10479

Illustrations

Worked examples

Example 1 — a first encounter with Practolol

Start with the simplest possible case. Write down what Practolol claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Practolol before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Practolol ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Practolol

In research: Practolol appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Practolol in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Practolol is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acetanilides, Beta blockers, Hepatotoxins, so understanding it makes those chapters shorter.
In everyday life: Look for Practolol outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Practolol in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Practolol means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Practolol out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Practolol in simple terms?

Why does Practolol matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Practolol?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Practolol.