Tomé la medicina ayer.

Tomé is the first-person singular form of tomar in the pretérito indefinido (the simple past).

So:

• tomar = to take
• tomé = I took

In this sentence, Tomé la medicina ayer, it means I took the medicine yesterday.

Because the action happened at a specific completed time in the past, Spanish uses the preterite here.

The accent mark in tomé shows both pronunciation and meaning.

• tomé = I took
• tome = a different form, such as a formal command or present subjunctive form of tomar

The accent tells you the stress falls on the last syllable: to-MÉ.

So the accent is important. Without it, it would be a different word/form.

Because Spanish often leaves out subject pronouns when they are not needed.

The ending -é in tomé already tells you the subject is I. So yo is optional.

Both are correct:

• Tomé la medicina ayer.
• Yo tomé la medicina ayer.

Using yo can add emphasis or contrast, for example:

• Yo tomé la medicina, pero él no.
  I took the medicine, but he didn’t.

La medicina uses the definite article la, meaning the medicine.

Spanish often uses articles in places where English sometimes does not. In this sentence, la medicina usually refers to a specific medicine that is already known from context.

For example:

• Tomé la medicina ayer = I took the medicine yesterday
• Necesito medicina = I need medicine

So here, la suggests a particular medicine, not medicine in general.

Yes, medicina is a feminine noun, which is why it uses la:

• la medicina

Many Spanish nouns ending in -a are feminine, and medicina is one of them.

That also affects adjectives:

• la medicina correcta = the correct medicine

Yes. Tomar is very commonly used for taking medicine.

In Spanish, tomar can mean several things depending on context, including:

• to take
• to drink
• to have

So:

• tomar la medicina = to take the medicine
• tomar un café = to have a coffee / drink a coffee

Even though tomar can literally mean drink in some contexts, with medicine it is naturally understood as take medicine.

Yes, you could.

Me tomé la medicina ayer is also natural and often means something like I took my medicine yesterday or I took the medicine yesterday, sometimes with a slight sense of completing the action.

The me here does not always translate directly into English. It can add a nuance of personal involvement or completion.

Compare:

• Tomé la medicina ayer = I took the medicine yesterday
• Me tomé la medicina ayer = I took the medicine yesterday / I took all of it / I went ahead and took it

In everyday speech, both are possible, but tomé la medicina ayer is simpler and very straightforward.

Ayer means yesterday, and it is an adverb of time.

It can go at the end, as in your sentence:

• Tomé la medicina ayer.

But it can also go at the beginning:

• Ayer tomé la medicina.

Both are correct. The difference is usually just focus or style:

• Tomé la medicina ayer = neutral
• Ayer tomé la medicina = slightly more emphasis on yesterday

The sentence uses the preterite because it refers to a completed action at a specific time:

• Tomé la medicina ayer = I took the medicine yesterday

The word ayer points to a finished time in the past, which often goes with the preterite.

If you used the imperfect, it would mean something different:

• Tomaba la medicina = I was taking the medicine / I used to take the medicine

So:

• tomé = one completed action
• tomaba = ongoing, habitual, or background action in the past

A simple pronunciation guide is:

toh-MEH la meh-dee-SEE-na ah-YEHR

A few tips:

• tomé → stress the last syllable: to-MÉ
• medicina → in Spain, the c before i is usually pronounced like the th in thin: meh-dee-THEE-na
• ayer → roughly ah-YEHR

In much of Spain, a more Spain-specific pronunciation would sound like:

toh-MEH la meh-dee-THEE-na ah-YEHR

In a very literal sense, tomar can sometimes overlap with drink, especially with liquid things. But in this sentence, the natural English translation is I took the medicine yesterday.

Spanish uses tomar broadly, so with medicine, English normally says take, not drink, unless you specifically want to emphasize that it was a liquid medicine.

So the best translation is still:

• Tomé la medicina ayer = I took the medicine yesterday

Yes, but it changes the feel slightly.

• Tomé la medicina ayer = I took the medicine yesterday
  → a specific medicine
• Ayer tomé medicina = I took medicine yesterday
  → more general

So if you are talking about a particular medicine already known in the conversation, la medicina is more likely. If you mean medicine in a general sense, dropping the article can work.

It is neutral. Nothing in the sentence is especially formal or informal.

• Tomé la medicina ayer works in everyday conversation
• It would also be fine in writing, depending on context

The sentence does not contain any slang or colloquial structure, so it is a standard, natural Spanish sentence.